Define alter cli flag

This flag not really documented, hopefully this clears up the intent.
Add some hints and tips for using RDS
2020-11-13 15:24:15 -07:00 · 2020-11-13 15:23:55 -07:00
1047 changed files with 186367 additions and 198037 deletions
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -5,15 +5,15 @@ on: [pull_request]
 jobs:
  build:

-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

-    - name: Set up Go
+    - name: Set up Go 1.14
      uses: actions/setup-go@v1
      with:
-        go-version: 1.17
+        go-version: 1.14

    - name: Build
      run: script/cibuild
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@ -1,25 +0,0 @@
-name: "CodeQL analysis"
-
-on: 
-  push:
-  pull_request:
-  schedule:
-    - cron: '0 0 * * 0'
-
-jobs:
-  codeql:
-
-    strategy:
-      fail-fast: false
-
-    runs-on: ubuntu-latest # windows-latest and ubuntu-latest are supported. macos-latest is not supported at this time. 
-
-    steps:
-    - name: Checkout repository
-      uses: actions/checkout@v2
-        
-    - name: Initialize CodeQL 
-      uses: github/codeql-action/init@v1
-    
-    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
--- a/.github/workflows/golangci-lint.yml
+++ b/.github/workflows/golangci-lint.yml
@ -1,23 +0,0 @@
-name: golangci-lint
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-permissions:
-  contents: read
-  # Optional: allow read access to pull request. Use with `only-new-issues` option.
-  # pull-requests: read
-jobs:
-  golangci:
-    name: lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/setup-go@v3
-        with:
-          go-version: 1.17
-      - uses: actions/checkout@v3
-      - name: golangci-lint
-        uses: golangci/golangci-lint-action@v3
-        with:
-          version: v1.46.2
--- a/.github/workflows/replica-tests.yml
+++ b/.github/workflows/replica-tests.yml
@ -5,20 +5,15 @@ on: [pull_request]
 jobs:
  build:

-    runs-on: ubuntu-20.04
-    strategy:
-      matrix:
-        version: [mysql-5.7.25,mysql-8.0.16,PerconaServer-8.0.21]
+    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

-    - name: Set up Go
+    - name: Set up Go 1.14
      uses: actions/setup-go@v1
      with:
-        go-version: 1.17
+        go-version: 1.14

    - name: migration tests
-      env:
-        TEST_MYSQL_VERSION: ${{ matrix.version }}
      run:  script/cibuild-gh-ost-replica-tests
--- a/.golangci.yml
+++ b/.golangci.yml
@ -1,30 +0,0 @@
-run:
-  timeout: 5m
-linters:
-  disable:
-    - errcheck
-  enable:
-    - bodyclose
-    - containedctx
-    - contextcheck
-    - dogsled
-    - durationcheck
-    - errname
-    - errorlint
-    - execinquery
-    - gofmt
-    - ifshort
-    - misspell
-    - nilerr
-    - nilnil
-    - noctx
-    - nolintlint
-    - nosprintfhostport
-    - prealloc
-    - rowserrcheck
-    - sqlclosecheck
-    - unconvert
-    - unparam
-    - unused
-    - wastedassign
-    - whitespace
--- a/Dockerfile.packaging
+++ b/Dockerfile.packaging
@ -1,4 +1,6 @@
-FROM golang:1.17
+#
+
+FROM golang:1.14.7

 RUN apt-get update
 RUN apt-get install -y ruby ruby-dev rubygems build-essential
--- a/Dockerfile.test
+++ b/Dockerfile.test
@ -1,4 +1,4 @@
-FROM golang:1.17
+FROM golang:1.14.7
 LABEL maintainer="github@github.com"

 RUN apt-get update
--- a/README.md
+++ b/README.md
@ -1,6 +1,6 @@
 # gh-ost

-[![ci](https://github.com/github/gh-ost/actions/workflows/ci.yml/badge.svg)](https://github.com/github/gh-ost/actions/workflows/ci.yml) [![replica-tests](https://github.com/github/gh-ost/actions/workflows/replica-tests.yml/badge.svg)](https://github.com/github/gh-ost/actions/workflows/replica-tests.yml) [![downloads](https://img.shields.io/github/downloads/github/gh-ost/total.svg)](https://github.com/github/gh-ost/releases) [![release](https://img.shields.io/github/release/github/gh-ost.svg)](https://github.com/github/gh-ost/releases)
+[![build status](https://travis-ci.org/github/gh-ost.svg)](https://travis-ci.org/github/gh-ost) [![downloads](https://img.shields.io/github/downloads/github/gh-ost/total.svg)](https://github.com/github/gh-ost/releases) [![release](https://img.shields.io/github/release/github/gh-ost.svg)](https://github.com/github/gh-ost/releases)

 #### GitHub's online schema migration for MySQL <img src="doc/images/gh-ost-logo-light-160.png" align="right">

@ -65,7 +65,6 @@ Also see:
 - [the fine print](doc/the-fine-print.md)
 - [Community questions](https://github.com/github/gh-ost/issues?q=label%3Aquestion)
 - [Using `gh-ost` on AWS RDS](doc/rds.md)
- [Using `gh-ost` on Azure Database for MySQL](doc/azure.md)

 ## What's in a name?

@ -95,7 +94,7 @@ Please see [Coding gh-ost](doc/coding-ghost.md) for a guide to getting started d

 [Download latest release here](https://github.com/github/gh-ost/releases/latest)

-`gh-ost` is a Go project; it is built with Go `1.15` and above. To build on your own, use either:
+`gh-ost` is a Go project; it is built with Go `1.14` and above. To build on your own, use either:
 - [script/build](https://github.com/github/gh-ost/blob/master/script/build) - this is the same build script used by CI hence the authoritative; artifact is `./bin/gh-ost` binary.
 - [build.sh](https://github.com/github/gh-ost/blob/master/build.sh) for building `tar.gz` artifacts in `/tmp/gh-ost`

--- a/2
+++ b/2
@ -1 +1 @@
-1.1.2
+1.1.0
--- a/build.sh
+++ b/build.sh
@ -18,32 +18,30 @@ function build {
  GOOS=$3
  GOARCH=$4

-  if ! go version | egrep -q 'go1\.(1[5-9]|[2-9][0-9]{1})' ; then
-    echo "go version must be 1.15 or above"
+  if ! go version | egrep -q 'go(1\.1[456])' ; then
+    echo "go version must be 1.14 or above"
    exit 1
  fi

-  echo "Building ${osname}-${GOARCH} binary"
+  echo "Building ${osname} binary"
  export GOOS
  export GOARCH
  go build -ldflags "$ldflags" -o $buildpath/$target go/cmd/gh-ost/main.go

  if [ $? -ne 0 ]; then
-      echo "Build failed for ${osname} ${GOARCH}."
+      echo "Build failed for ${osname}"
      exit 1
  fi

-  (cd $buildpath && tar cfz ./gh-ost-binary-${osshort}-${GOARCH}-${timestamp}.tar.gz $target)
+  (cd $buildpath && tar cfz ./gh-ost-binary-${osshort}-${timestamp}.tar.gz $target)

-  # build RPM and deb for Linux, x86-64 only
-  if [ "$GOOS" == "linux" ] && [ "$GOARCH" == "amd64" ] ; then
+  if [ "$GOOS" == "linux" ] ; then
    echo "Creating Distro full packages"
    builddir=$(setuptree)
    cp $buildpath/$target $builddir/gh-ost/usr/bin
    cd $buildpath
-    fpm -v "${RELEASE_VERSION}" --epoch 1 -f -s dir -n gh-ost -m 'GitHub' --description "GitHub's Online Schema Migrations for MySQL " --url "https://github.com/github/gh-ost" --vendor "GitHub" --license "Apache 2.0" -C $builddir/gh-ost --prefix=/ -t rpm --rpm-rpmbuild-define "_build_id_links none" --rpm-os linux .
-    fpm -v "${RELEASE_VERSION}" --epoch 1 -f -s dir -n gh-ost -m 'GitHub' --description "GitHub's Online Schema Migrations for MySQL " --url "https://github.com/github/gh-ost" --vendor "GitHub" --license "Apache 2.0" -C $builddir/gh-ost --prefix=/ -t deb --deb-no-default-config-files .
-    cd -
+    fpm -v "${RELEASE_VERSION}" --epoch 1 -f -s dir -n gh-ost -m 'shlomi-noach <shlomi-noach+gh-ost-deb@github.com>' --description "GitHub's Online Schema Migrations for MySQL " --url "https://github.com/github/gh-ost" --vendor "GitHub" --license "Apache 2.0" -C $builddir/gh-ost --prefix=/ -t rpm .
+    fpm -v "${RELEASE_VERSION}" --epoch 1 -f -s dir -n gh-ost -m 'shlomi-noach <shlomi-noach+gh-ost-deb@github.com>' --description "GitHub's Online Schema Migrations for MySQL " --url "https://github.com/github/gh-ost" --vendor "GitHub" --license "Apache 2.0" -C $builddir/gh-ost --prefix=/ -t deb --deb-no-default-config-files .
  fi
 }

@ -64,15 +62,10 @@ main() {
  mkdir -p ${buildpath}
  rm -rf ${buildpath:?}/*
  build GNU/Linux linux linux amd64
-  build GNU/Linux linux linux arm64
-  build macOS osx darwin amd64
-  build macOS osx darwin arm64
+  # build macOS osx darwin amd64

  echo "Binaries found in:"
  find $buildpath/gh-ost* -type f -maxdepth 1
-
-  echo "Checksums:"
-  (cd $buildpath && shasum -a256 gh-ost* 2>/dev/null)
 }

 main "$@"
--- a/doc/azure.md
+++ b/doc/azure.md
@ -1,26 +0,0 @@
-`gh-ost` has been updated to work with Azure Database for MySQL however due to GitHub does not use it, this documentation is community driven so if you find a bug please [open an issue][new_issue]!
-
-# Azure Database for MySQL
-
-## Limitations
-
- `gh-ost` runs should be setup use [`--assume-rbr`][assume_rbr_docs] and use `binlog_row_image=FULL`.
- Azure Database for MySQL does not use same user name suffix for master and replica, so master host, user and password need to be pointed out. 
-
-## Step
-1. Change the replica server's `binlog_row_image` from `MINIMAL` to `FULL`. See [guide](https://docs.microsoft.com/en-us/azure/mysql/howto-server-parameters) on Azure document.
-2. Use your `gh-ost` always with additional 5 parameter
-```{bash}
-gh-ost \
--azure \
--assume-master-host=master-server-dns-name \
--master-user="master-user-name" \
--master-password="master-password" \
--assume-rbr \
-[-- other paramters you need]
-```
-
-
-[new_issue]: https://github.com/github/gh-ost/issues/new
-[assume_rbr_docs]: https://github.com/github/gh-ost/blob/master/doc/command-line-flags.md#assume-rbr
-[migrate_test_on_replica_docs]: https://github.com/github/gh-ost/blob/master/doc/cheatsheet.md#c-migratetest-on-replica
--- a/doc/coding-ghost.md
+++ b/doc/coding-ghost.md
@ -5,7 +5,7 @@
 Getting started with gh-ost development is simple!

 - First obtain the repository with `git clone` or `go get`.
- From inside of the repository run `script/cibuild`.
+- From inside of the repository run `script/cibuild`
 - This will bootstrap the environment if needed, format the code, build the code, and then run the unit test.

 ## CI build workflow
@ -14,12 +14,6 @@ Getting started with gh-ost development is simple!

 If additional steps are needed, please add them into this workflow so that the workflow remains simple.

-## `golang-ci` linter
-
-To enfore best-practices, Pull Requests are automatically linted by [`golang-ci`](https://golangci-lint.run/). The linter config is located at [`.golangci.yml`](https://github.com/github/gh-ost/blob/master/.golangci.yml) and the `golangci-lint` GitHub Action is located at [`.github/workflows/golangci-lint.yml`](https://github.com/github/gh-ost/blob/master/.github/workflows/golangci-lint.yml).
-
-To run the `golang-ci` linters locally _(recommended before push)_, use `script/lint`.
-
 ## Notes:

 Currently, `script/ensure-go-installed` will install `go` for Mac OS X and Linux. We welcome PR's to add other platforms.
--- a/doc/command-line-flags.md
+++ b/doc/command-line-flags.md
@ -6,14 +6,6 @@ A more in-depth discussion of various `gh-ost` command line flags: implementatio

 Add this flag when executing on Aliyun RDS.

-### allow-zero-in-date
-
-Allows the user to make schema changes that include a zero date or zero in date (e.g. adding a `datetime default '0000-00-00 00:00:00'` column), even if global `sql_mode` on MySQL has `NO_ZERO_IN_DATE,NO_ZERO_DATE`.
-
-###  azure
-
-Add this flag when executing on Azure Database for MySQL.
-
 ### allow-master-master

 See [`--assume-master-host`](#assume-master-host).
@ -24,9 +16,13 @@ By default, `gh-ost` would like you to connect to a replica, from where it figur

 If, for some reason, you do not wish `gh-ost` to connect to a replica, you may connect it directly to the master and approve this via `--allow-on-master`.

+### alter
+
+This manadatory flag is the `ALTER` statement migrated to the ghost table.
+
 ### approve-renamed-columns

-When your migration issues a column rename (`change column old_name new_name ...`) `gh-ost` analyzes the statement to try and associate the old column name with new column name. Otherwise, the new structure may also look like some column was dropped and another was added.
+When your migration issues a column rename (`change column old_name new_name ...`) `gh-ost` analyzes the statement to try and associate the old column name with new column name. Otherwise the new structure may also look like some column was dropped and another was added.

 `gh-ost` will print out what it thinks the _rename_ implied, but will not issue the migration unless you provide with `--approve-renamed-columns`.

@ -36,7 +32,7 @@ If you think `gh-ost` is mistaken and that there's actually no _rename_ involved

 `gh-ost` infers the identity of the master server by crawling up the replication topology. You may explicitly tell `gh-ost` the identity of the master host via `--assume-master-host=the.master.com`. This is useful in:

- _master-master_ topologies (together with [`--allow-master-master`](#allow-master-master)), where `gh-ost` can arbitrarily pick one of the co-masters, and you prefer that it picks a specific one
+- _master-master_ topologies (together with [`--allow-master-master`](#allow-master-master)), where `gh-ost` can arbitrarily pick one of the co-masters and you prefer that it picks a specific one
 - _tungsten replicator_ topologies (together with [`--tungsten`](#tungsten)), where `gh-ost` is unable to crawl and detect the master

 ### assume-rbr
@ -45,25 +41,6 @@ If you happen to _know_ your servers use RBR (Row Based Replication, i.e. `binlo
 Skipping this step means `gh-ost` would not need the `SUPER` privilege in order to operate.
 You may want to use this on Amazon RDS.

-### attempt-instant-ddl
-
-MySQL 8.0 supports "instant DDL" for some operations. If an alter statement can be completed with instant DDL, only a metadata change is required internally. Instant operations include:
-
- Adding a column
- Dropping a column
- Dropping an index
- Extending a varchar column
- Adding a virtual generated column
-
-It is not reliable to parse the `ALTER` statement to determine if it is instant or not. This is because the table might be in an older row format, or have some other incompatibility that is difficult to identify.
-
-`--attempt-instant-ddl` is disabled by default, but the risks of enabling it are relatively minor: `gh-ost` may need to acquire a metadata lock at the start of the operation. This is not a problem for most scenarios, but it could be a problem for users that start the DDL during a period with long running transactions.
-
-`gh-ost` will automatically fallback to the normal DDL process if the attempt to use instant DDL is unsuccessful.
-
-### binlogsyncer-max-reconnect-attempts
-`--binlogsyncer-max-reconnect-attempts=0`, the maximum number of attempts to re-establish a broken inspector connection for sync binlog. `0` or `negative number` means infinite retry, default `0`
-
 ### conf

 `--conf=/path/to/my.cnf`: file where credentials are specified. Should be in (or contain) the following format:
@ -84,13 +61,7 @@ Comma delimited status-name=threshold, same format as [`--max-load`](#max-load).

 `--critical-load` defines a threshold that, when met, `gh-ost` panics and bails out. The default behavior is to bail out immediately when meeting this threshold.

-This may sometimes lead to migrations bailing out on a very short spike, that, while in itself is impacting production and is worth investigating, isn't reason enough to kill a 10-hour migration.
-
-### critical-load-hibernate-seconds
-
-When `--critical-load-hibernate-seconds` is non-zero (e.g. `--critical-load-hibernate-seconds=300`), `critical-load` does not panic and bail out; instead, `gh-ost` goes into hibernation for the specified duration. It will not read/write anything from/to any server during this time.  Execution then continues upon waking from hibernation.
-
-If `critical-load` is met again, `gh-ost` will repeat this cycle, and never panic and bail out.
+This may sometimes lead to migrations bailing out on a very short spike, that, while in itself is impacting production and is worth investigating, isn't reason enough to kill a 10 hour migration.

 ### critical-load-interval-millis

@ -127,7 +98,7 @@ Noteworthy is that setting `--dml-batch-size` to higher value _does not_ mean `g

 ### exact-rowcount

-A `gh-ost` execution need to copy whatever rows you have in your existing table onto the ghost table. This can and often will be, a large number. Exactly what that number is?
+A `gh-ost` execution need to copy whatever rows you have in your existing table onto the ghost table. This can, and often be, a large number. Exactly what that number is?
 `gh-ost` initially estimates the number of rows in your table by issuing an `explain select * from your_table`. This will use statistics on your table and return with a rough estimate. How rough? It might go as low as half or as high as double the actual number of rows in your table. This is the same method as used in [`pt-online-schema-change`](https://www.percona.com/doc/percona-toolkit/2.2/pt-online-schema-change.html).

 `gh-ost` also supports the `--exact-rowcount` flag. When this flag is given, two things happen:
@ -164,10 +135,6 @@ Add this flag when executing on a 1st generation Google Cloud Platform (GCP).

 Default 100. See [`subsecond-lag`](subsecond-lag.md) for details.

-### hooks-status-interval
-
-Defaults to 60 seconds. Configures how often the `gh-ost-on-status` hook is called, see [`hooks`](hooks.md) for full details on how to use hooks.
-
 ### initially-drop-ghost-table

 `gh-ost` maintains two tables while migrating: the _ghost_ table (which is synced from your original table and finally replaces it) and a changelog table, which is used internally for bookkeeping. By default, it panics and aborts if it sees those tables upon startup. Provide `--initially-drop-ghost-table` and `--initially-drop-old-table` to let `gh-ost` know it's OK to drop them beforehand.
@ -214,9 +181,6 @@ Optionally involve the process ID, for example: `--replica-server-id=$((10000000
 It's on you to choose a number that does not collide with another `gh-ost` or another running replica.
 See also: [`concurrent-migrations`](cheatsheet.md#concurrent-migrations) on the cheatsheet.

-### serve-socket-file
-
-Defaults to an auto-determined and advertised upon startup file. Defines Unix socket file to serve on.
 ### skip-foreign-key-checks

 By default `gh-ost` verifies no foreign keys exist on the migrated table. On servers with large number of tables this check can take a long time. If you're absolutely certain no foreign keys exist (table does not reference other table nor is referenced by other tables) and wish to save the check time, provide with `--skip-foreign-key-checks`.
@ -249,18 +213,6 @@ Allows `gh-ost` to connect to the MySQL servers using encrypted connections, but

 `--ssl-key=/path/to/ssl-key.key`: SSL private key file (in PEM format).

-### storage-engine
-Default is `innodb`, and `rocksdb` support is currently experimental. InnoDB and RocksDB are both transactional engines, supporting both shared and exclusive row locks.
-
-But RocksDB currently lacks a few features support compared to InnoDB:
- Gap Locks
- Foreign Key
- Generated Columns
- Spatial
- Geometry
-
-When `--storage-engine=rocksdb`, `gh-ost` will make some changes necessary (e.g. sets isolation level to `READ_COMMITTED`) to support RocksDB.
-
 ### test-on-replica

 Issue the migration on a replica; do not modify data on master. Useful for validating, testing and benchmarking. See [`testing-on-replica`](testing-on-replica.md)
@ -275,15 +227,7 @@ Provide a command delimited list of replicas; `gh-ost` will throttle when any of

 ### throttle-http

-Provide an HTTP endpoint; `gh-ost` will issue `HEAD` requests on given URL and throttle whenever response status code is not `200`. The URL can be queried and updated dynamically via [interactive commands](interactive-commands.md). Empty URL disables the HTTP check.
-
-### throttle-http-interval-millis
-
-Defaults to 100. Configures the HTTP throttle check interval in milliseconds.
-
-### throttle-http-timeout-millis
-
-Defaults to 1000 (1 second). Configures the HTTP throttler check timeout in milliseconds.
+Provide a HTTP endpoint; `gh-ost` will issue `HEAD` requests on given URL and throttle whenever response status code is not `200`. The URL can be queried and updated dynamically via [interactive commands](interactive-commands.md). Empty URL disables the HTTP check.

 ### timestamp-old-table

--- a/doc/hooks.md
+++ b/doc/hooks.md
@ -66,9 +66,7 @@ The following variables are available on all hooks:
 - `GH_OST_ESTIMATED_ROWS` - estimated total rows in table
 - `GH_OST_COPIED_ROWS` - number of rows copied by `gh-ost`
 - `GH_OST_INSPECTED_LAG` - lag in seconds (floating point) of inspected server
- `GH_OST_HEARTBEAT_LAG` - lag in seconds (floating point) of heartbeat
 - `GH_OST_PROGRESS` - progress pct ([0..100], floating point) of migration
- `GH_OST_ETA_SECONDS` - estimated duration until migration finishes in seconds
 - `GH_OST_MIGRATED_HOST`
 - `GH_OST_INSPECTED_HOST`
 - `GH_OST_EXECUTING_HOST`
--- a/doc/interactive-commands.md
+++ b/doc/interactive-commands.md
@ -18,8 +18,6 @@ Both interfaces may serve at the same time. Both respond to simple text command,
 - `status`: returns a detailed status summary of migration progress and configuration
 - `sup`: returns a brief status summary of migration progress
 - `coordinates`: returns recent (though not exactly up to date) binary log coordinates of the inspected server
- `applier`: returns the hostname of the applier
- `inspector`: returns the hostname of the inspector
 - `chunk-size=<newsize>`: modify the `chunk-size`; applies on next running copy-iteration
 - `dml-batch-size=<newsize>`: modify the `dml-batch-size`; applies on next applying of binary log events
 - `max-lag-millis=<max-lag>`: modify the maximum replication lag threshold (milliseconds, minimum value is `100`, i.e. `0.1` second)
--- a/doc/rds.md
+++ b/doc/rds.md
@ -5,7 +5,9 @@
 ## Limitations

 - No `SUPER` privileges.
+  - Editing `binlog_format` not allowed, see next bullet.
 - `gh-ost` runs should be setup use [`--assume-rbr`][assume_rbr_docs] and use `binlog_format=ROW`.
+  - See [this tip](#binlog_format) on how to change the `binlog_format`.
 - Aurora does not allow editing of the `read_only` parameter. While it is defined as `{TrueIfReplica}`, the parameter is non-modifiable field.

 ## Aurora
@ -53,3 +55,10 @@ Before trying to run any `gh-ost` migrations you will want to confirm the follow
 [ghost_hooks]: https://github.com/github/gh-ost/blob/master/doc/hooks.md
 [ghost_rds_issue_tracking]: https://github.com/github/gh-ost/issues/163
 [aws_replication_docs_bin_log_filtering]: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Replication.html#AuroraMySQL.Replication.Performance
+
+## Other Tips & Tricks
+
+## binlog_format
+
+On a normal RDS instance, if you need to switch to `binlog_format=ROW`, you can do so by creating a [RDS Parameter Group](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithParamGroups.html).
+During the Parameter Group creation process, set `binlog_format` to `ROW`. After creating the Parameter group, you can modify you RDS instance to use it.
--- a/doc/requirements-and-limitations.md
+++ b/doc/requirements-and-limitations.md
@ -2,8 +2,6 @@

 ### Requirements

- `gh-ost` currently requires MySQL versions 5.7 and greater.
-
 - You will need to have one server serving Row Based Replication (RBR) format binary logs. Right now `FULL` row image is supported. `MINIMAL` to be supported in the near future. `gh-ost` prefers to work with replicas. You may [still have your master configured with Statement Based Replication](migrating-with-sbr.md) (SBR).

 - If you are using a replica, the table must have an identical schema between the master and replica.
@ -20,8 +18,6 @@ The `SUPER` privilege is required for `STOP SLAVE`, `START SLAVE` operations. Th
 - Switching your `binlog_format` to `ROW`, in the case where it is _not_ `ROW` and you explicitly specified `--switch-to-rbr`
  - If your replication is already in RBR (`binlog_format=ROW`) you can specify `--assume-rbr` to avoid the `STOP SLAVE/START SLAVE` operations, hence no need for `SUPER`.

- `gh-ost` uses the `REPEATABLE_READ` transaction isolation level for all MySQL connections, regardless of the server default.
-
 - Running `--test-on-replica`: before the cut-over phase, `gh-ost` stops replication so that you can compare the two tables and satisfy that the migration is sound.

 ### Limitations
@ -45,7 +41,6 @@ The `SUPER` privilege is required for `STOP SLAVE`, `START SLAVE` operations. Th
 - Amazon RDS works, but has its own [limitations](rds.md).
 - Google Cloud SQL works, `--gcp` flag required.
 - Aliyun RDS works, `--aliyun-rds` flag required.
- Azure Database for MySQL works, `--azure` flag required, and have detailed document about it. (azure.md)

 - Multisource is not supported when migrating via replica. It _should_ work (but never tested) when connecting directly to master (`--allow-on-master`)

--- a/doc/shared-key.md
+++ b/doc/shared-key.md
@ -29,7 +29,7 @@ CREATE TABLE tbl (

 (This is also the definition of the _ghost_ table, except that that table would be called `_tbl_gho`). 

-In this migration, the _before_ and _after_ versions contain the same unique not-null key (the PRIMARY KEY). To run this migration, `gh-ost` would iterate through the `tbl` table using the primary key, copy rows from `tbl` to the _ghost_ table `_tbl_gho` in primary key order, while also applying the binlog event writes from `tbl` onto `_tbl_gho`.
+In this migration, the _before_ and _after_ versions contain the same unique not-null key (the PRIMARY KEY). To run this migration, `gh-ost` would iterate through the `tbl` table using the primary key, copy rows from `tbl` to the _ghost_ table `_tbl_gho` in primary key order, while also applying the binlog event writes from `tble` onto `_tbl_gho`.

 The applying of the binlog events is what requires the shared unique key. For example, an `UPDATE` statement to `tbl` translates to a `REPLACE` statement which `gh-ost` applies to `_tbl_gho`. A `REPLACE` statement expects to insert or replace an existing row based on its row's values and the table's unique key constraints. In particular, if inserting that row would result in a unique key violation (e.g., a row with that primary key already exists), it would _replace_ that existing row with the new values.

--- a/doc/throttle.md
+++ b/doc/throttle.md
@ -38,7 +38,7 @@ Note that you may dynamically change both `--max-lag-millis` and the `throttle-c

  `--max-load='Threads_running=100,Threads_connected=500'`

-  Metrics must be valid, numeric [status variables](https://dev.mysql.com/doc/refman/5.7/en/server-status-variables.html)
+  Metrics must be valid, numeric [status variables](http://dev.mysql.com/doc/refman/5.6/en/server-status-variables.html)

 #### Throttle query

@ -97,7 +97,7 @@ Copy: 0/2915 0.0%; Applied: 0; Backlog: 0/100; Elapsed: 42s(copy), 42s(total); s

 Throttling time is limited by the availability of the binary logs. When throttling begins, `gh-ost` suspends reading the binary logs, and expects to resume reading from same binary log where it paused.

-Your availability of binary logs is typically determined by the [expire_logs_days](https://dev.mysql.com/doc/refman/5.7/en/replication-options-binary-log.html#sysvar_expire_logs_days) variable. If you have `expire_logs_days = 10` (or check `select @@global.expire_logs_days`), then you should be able to throttle for up to `10` days.
+Your availability of binary logs is typically determined by the [expire_logs_days](https://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_expire_logs_days) variable. If you have `expire_logs_days = 10` (or check `select @@global.expire_logs_days`), then you should be able to throttle for up to `10` days.

 Having said that, throttling for so long is far fetching, in that the `gh-ost` process itself must be kept alive during that time; and the amount of binary logs to process once it resumes will potentially take days to replay.

--- a/doc/triggerless-design.md
+++ b/doc/triggerless-design.md
@ -112,7 +112,7 @@ It is also interesting to observe that `gh-ost` is the only application writing

 When `gh-ost` pauses (throttles), it issues no writes on the ghost table. Because there are no triggers, write workload is decoupled from the `gh-ost` write workload. And because we're using an asynchronous approach, the algorithm already handles a time difference between a master write time and the ghost apply time. A difference of a few microseconds is no different from a difference of minutes or hours.

-When `gh-ost` [throttles](throttle.md), either by replication lag, `max-load` setting or an explicit [interactive user command](interactive-commands.md), the master is back to normal. It sees no more writes on the ghost table.
+When `gh-ost` [throttles](throttle.md), either by replication lag, `max-load` setting or and explicit [interactive user command](interactive-commands.md), the master is back to normal. It sees no more writes on the ghost table.
 An exception is the ongoing heartbeat writes onto the changelog table, which we consider to be negligible.

 #### Testability
--- a/doc/why-triggerless.md
+++ b/doc/why-triggerless.md
@ -7,7 +7,7 @@ Existing MySQL schema migration tools:
 - [LHM](https://github.com/soundcloud/lhm)
 - [oak-online-alter-table](https://github.com/shlomi-noach/openarkkit)

-are all using [triggers](https://dev.mysql.com/doc/refman/5.7/en/triggers.html) to propagate live changes on your table onto a ghost/shadow table that is slowly being synchronized. The tools not all work the same: while most use a synchronous approach (all changes applied on the ghost table), the Facebook tool uses an asynchronous approach (changes are appended to a changelog table, later reviewed and applied on ghost table).
+are all using [triggers](http://dev.mysql.com/doc/refman/5.6/en/triggers.html) to propagate live changes on your table onto a ghost/shadow table that is slowly being synchronized. The tools not all work the same: while most use a synchronous approach (all changes applied on the ghost table), the Facebook tool uses an asynchronous approach (changes are appended to a changelog table, later reviewed and applied on ghost table).

 Use of triggers simplifies a lot of the flow in doing a live table migration, but also poses some limitations or difficulties. Here are reasons why we choose to [design a triggerless solution](triggerless-design.md) to schema migrations.

--- a/go.mod
+++ b/go.mod
@ -1,27 +0,0 @@
-module github.com/github/gh-ost
-
-go 1.17
-
-require (
-	github.com/go-ini/ini v1.62.0
-	github.com/go-mysql-org/go-mysql v1.3.0
-	github.com/go-sql-driver/mysql v1.6.0
-	github.com/openark/golib v0.0.0-20210531070646-355f37940af8
-	github.com/satori/go.uuid v1.2.0
-	golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83
-	golang.org/x/net v0.0.0-20210224082022-3d97a244fca7
-	golang.org/x/text v0.3.6
-)
-
-require (
-	github.com/pingcap/errors v0.11.5-0.20201126102027-b0a155152ca3 // indirect
-	github.com/shopspring/decimal v0.0.0-20180709203117-cd690d0c9e24 // indirect
-	github.com/siddontang/go v0.0.0-20180604090527-bdc77568d726 // indirect
-	github.com/siddontang/go-log v0.0.0-20180807004314-8d05993dda07 // indirect
-	github.com/smartystreets/goconvey v1.6.4 // indirect
-	go.uber.org/atomic v1.7.0 // indirect
-	golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
-	golang.org/x/term v0.0.0-20220526004731-065cf7ba2467 // indirect
-	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
-	gopkg.in/ini.v1 v1.62.0 // indirect
-)
--- a/go.sum
+++ b/go.sum
@ -1,136 +0,0 @@
-github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
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-github.com/cznic/mathutil v0.0.0-20181122101859-297441e03548/go.mod h1:e6NPNENfs9mPDVNRekM7lKScauxd5kXTr1Mfyig6TDM=
-github.com/cznic/parser v0.0.0-20160622100904-31edd927e5b1/go.mod h1:2B43mz36vGZNZEwkWi8ayRSSUXLfjL8OkbzwW4NcPMM=
-github.com/cznic/sortutil v0.0.0-20181122101858-f5f958428db8/go.mod h1:q2w6Bg5jeox1B+QkJ6Wp/+Vn0G/bo3f1uY7Fn3vivIQ=
-github.com/cznic/strutil v0.0.0-20171016134553-529a34b1c186/go.mod h1:AHHPPPXTw0h6pVabbcbyGRK1DckRn7r/STdZEeIDzZc=
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-golang.org/x/mod v0.0.0-20190513183733-4bf6d317e70e/go.mod h1:mXi4GBBbnImb6dmsKGUJ2LatrhH/nqhxcFungHvyanc=
-golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.0.0-20210224082022-3d97a244fca7 h1:OgUuv8lsRpBibGNbSizVwKWlysjaNzmC9gYMhPVfqFM=
-golang.org/x/net v0.0.0-20210224082022-3d97a244fca7/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 h1:v+OssWQX+hTHEmOBgwxdZxK4zHq3yOs8F9J7mk0PY8E=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20220526004731-065cf7ba2467 h1:CBpWXWQpIRjzmkkA+M7q9Fqnwd2mZr3AFqexg8YTfoM=
-golang.org/x/term v0.0.0-20220526004731-065cf7ba2467/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.6 h1:aRYxNxv6iGQlyVaZmk6ZgYEDa+Jg18DxebPSrd6bg1M=
-golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-golang.org/x/tools v0.0.0-20190621195816-6e04913cbbac/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
-golang.org/x/tools v0.0.0-20191029041327-9cc4af7d6b2c/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20201125231158-b5590deeca9b/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
-gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=
-gopkg.in/ini.v1 v1.62.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
-gopkg.in/natefinch/lumberjack.v2 v2.0.0/go.mod h1:l0ndWWf7gzL7RNwBG7wST/UCcT4T24xpD6X8LsfU/+k=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
--- a/go/base/context.go
+++ b/go/base/context.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -15,13 +15,14 @@ import (
 	"sync/atomic"
 	"time"

-	uuid "github.com/satori/go.uuid"
+	"github.com/satori/go.uuid"

 	"github.com/github/gh-ost/go/mysql"
 	"github.com/github/gh-ost/go/sql"
-	"github.com/openark/golib/log"
+	"github.com/outbrain/golib/log"

-	"github.com/go-ini/ini"
+	"gopkg.in/gcfg.v1"
+	gcfgscanner "gopkg.in/gcfg.v1/scanner"
 )

 // RowsEstimateMethod is the type of row number estimation
@ -51,7 +52,6 @@ const (
 const (
 	HTTPStatusOK       = 200
 	MaxEventsBatchSize = 1000
-	ETAUnknown         = math.MinInt64
 )

 var (
@ -82,8 +82,6 @@ type MigrationContext struct {
 	AlterStatement        string
 	AlterStatementOptions string // anything following the 'ALTER TABLE [schema.]table' from AlterStatement

-	countMutex               sync.Mutex
-	countTableRowsCancelFunc func()
 	CountTableRows           bool
 	ConcurrentCountTableRows bool
 	AllowedRunningOnMaster   bool
@ -92,7 +90,6 @@ type MigrationContext struct {
 	AssumeRBR                bool
 	SkipForeignKeyChecks     bool
 	SkipStrictMode           bool
-	AllowZeroInDate          bool
 	NullableUniqueKeyAllowed bool
 	ApproveRenamedColumns    bool
 	SkipRenamedColumns       bool
@ -100,8 +97,6 @@ type MigrationContext struct {
 	DiscardForeignKeys       bool
 	AliyunRDS                bool
 	GoogleCloudPlatform      bool
-	AzureMySQL               bool
-	AttemptInstantDDL        bool

 	config            ContextConfig
 	configMutex       *sync.Mutex
@ -144,7 +139,6 @@ type MigrationContext struct {
 	HooksHintMessage                    string
 	HooksHintOwner                      string
 	HooksHintToken                      string
-	HooksStatusIntervalSec              int64

 	DropServeSocket bool
 	ServeSocketFile string
@ -183,14 +177,9 @@ type MigrationContext struct {
 	RenameTablesEndTime                    time.Time
 	pointOfInterestTime                    time.Time
 	pointOfInterestTimeMutex               *sync.Mutex
-	lastHeartbeatOnChangelogTime           time.Time
-	lastHeartbeatOnChangelogMutex          *sync.Mutex
 	CurrentLag                             int64
 	currentProgress                        uint64
-	etaNanoseonds                          int64
-	ThrottleHTTPIntervalMillis             int64
 	ThrottleHTTPStatusCode                 int64
-	ThrottleHTTPTimeoutMillis              int64
 	controlReplicasLagResult               mysql.ReplicationLagResult
 	TotalRowsCopied                        int64
 	TotalDMLEventsApplied                  int64
@ -214,7 +203,6 @@ type MigrationContext struct {
 	OriginalTableColumns             *sql.ColumnList
 	OriginalTableVirtualColumns      *sql.ColumnList
 	OriginalTableUniqueKeys          [](*sql.UniqueKey)
-	OriginalTableAutoIncrement       uint64
 	GhostTableColumns                *sql.ColumnList
 	GhostTableVirtualColumns         *sql.ColumnList
 	GhostTableUniqueKeys             [](*sql.UniqueKey)
@ -232,8 +220,6 @@ type MigrationContext struct {

 	recentBinlogCoordinates mysql.BinlogCoordinates

-	BinlogSyncerMaxReconnectAttempts int
-
 	Log Logger
 }

@ -277,7 +263,6 @@ func NewMigrationContext() *MigrationContext {
 		MaxLagMillisecondsThrottleThreshold: 1500,
 		CutOverLockTimeoutSeconds:           3,
 		DMLBatchSize:                        10,
-		etaNanoseonds:                       ETAUnknown,
 		maxLoad:                             NewLoadMap(),
 		criticalLoad:                        NewLoadMap(),
 		throttleMutex:                       &sync.Mutex{},
@ -285,26 +270,12 @@ func NewMigrationContext() *MigrationContext {
 		throttleControlReplicaKeys:          mysql.NewInstanceKeyMap(),
 		configMutex:                         &sync.Mutex{},
 		pointOfInterestTimeMutex:            &sync.Mutex{},
-		lastHeartbeatOnChangelogMutex:       &sync.Mutex{},
 		ColumnRenameMap:                     make(map[string]string),
 		PanicAbort:                          make(chan error),
 		Log:                                 NewDefaultLogger(),
 	}
 }

-func (this *MigrationContext) SetConnectionConfig(storageEngine string) error {
-	var transactionIsolation string
-	switch storageEngine {
-	case "rocksdb":
-		transactionIsolation = "READ-COMMITTED"
-	default:
-		transactionIsolation = "REPEATABLE-READ"
-	}
-	this.InspectorConnectionConfig.TransactionIsolation = transactionIsolation
-	this.ApplierConnectionConfig.TransactionIsolation = transactionIsolation
-	return nil
-}
-
 func getSafeTableName(baseName string, suffix string) string {
 	name := fmt.Sprintf("_%s_%s", baseName, suffix)
 	if len(name) <= mysql.MaxTableNameLength {
@ -443,44 +414,10 @@ func (this *MigrationContext) IsTransactionalTable() bool {
 		{
 			return true
 		}
-	case "rocksdb":
-		{
-			return true
-		}
 	}
 	return false
 }

-// SetCountTableRowsCancelFunc sets the cancel function for the CountTableRows query context
-func (this *MigrationContext) SetCountTableRowsCancelFunc(f func()) {
-	this.countMutex.Lock()
-	defer this.countMutex.Unlock()
-
-	this.countTableRowsCancelFunc = f
-}
-
-// IsCountingTableRows returns true if the migration has a table count query running
-func (this *MigrationContext) IsCountingTableRows() bool {
-	this.countMutex.Lock()
-	defer this.countMutex.Unlock()
-
-	return this.countTableRowsCancelFunc != nil
-}
-
-// CancelTableRowsCount cancels the CountTableRows query context. It is safe to
-// call function even when IsCountingTableRows is false.
-func (this *MigrationContext) CancelTableRowsCount() {
-	this.countMutex.Lock()
-	defer this.countMutex.Unlock()
-
-	if this.countTableRowsCancelFunc == nil {
-		return
-	}
-
-	this.countTableRowsCancelFunc()
-	this.countTableRowsCancelFunc = nil
-}
-
 // ElapsedTime returns time since very beginning of the process
 func (this *MigrationContext) ElapsedTime() time.Duration {
 	return time.Since(this.StartTime)
@ -516,10 +453,6 @@ func (this *MigrationContext) MarkRowCopyEndTime() {
 	this.RowCopyEndTime = time.Now()
 }

-func (this *MigrationContext) TimeSinceLastHeartbeatOnChangelog() time.Duration {
-	return time.Since(this.GetLastHeartbeatOnChangelogTime())
-}
-
 func (this *MigrationContext) GetCurrentLagDuration() time.Duration {
 	return time.Duration(atomic.LoadInt64(&this.CurrentLag))
 }
@ -532,22 +465,6 @@ func (this *MigrationContext) SetProgressPct(progressPct float64) {
 	atomic.StoreUint64(&this.currentProgress, math.Float64bits(progressPct))
 }

-func (this *MigrationContext) GetETADuration() time.Duration {
-	return time.Duration(atomic.LoadInt64(&this.etaNanoseonds))
-}
-
-func (this *MigrationContext) SetETADuration(etaDuration time.Duration) {
-	atomic.StoreInt64(&this.etaNanoseonds, etaDuration.Nanoseconds())
-}
-
-func (this *MigrationContext) GetETASeconds() int64 {
-	nano := atomic.LoadInt64(&this.etaNanoseonds)
-	if nano < 0 {
-		return ETAUnknown
-	}
-	return nano / int64(time.Second)
-}
-
 // math.Float64bits([f=0..100])

 // GetTotalRowsCopied returns the accurate number of rows being copied (affected)
@ -575,20 +492,6 @@ func (this *MigrationContext) TimeSincePointOfInterest() time.Duration {
 	return time.Since(this.pointOfInterestTime)
 }

-func (this *MigrationContext) SetLastHeartbeatOnChangelogTime(t time.Time) {
-	this.lastHeartbeatOnChangelogMutex.Lock()
-	defer this.lastHeartbeatOnChangelogMutex.Unlock()
-
-	this.lastHeartbeatOnChangelogTime = t
-}
-
-func (this *MigrationContext) GetLastHeartbeatOnChangelogTime() time.Time {
-	this.lastHeartbeatOnChangelogMutex.Lock()
-	defer this.lastHeartbeatOnChangelogMutex.Unlock()
-
-	return this.lastHeartbeatOnChangelogTime
-}
-
 func (this *MigrationContext) SetHeartbeatIntervalMilliseconds(heartbeatIntervalMilliseconds int64) {
 	if heartbeatIntervalMilliseconds < 100 {
 		heartbeatIntervalMilliseconds = 100
@ -607,8 +510,8 @@ func (this *MigrationContext) SetMaxLagMillisecondsThrottleThreshold(maxLagMilli
 }

 func (this *MigrationContext) SetChunkSize(chunkSize int64) {
-	if chunkSize < 10 {
-		chunkSize = 10
+	if chunkSize < 100 {
+		chunkSize = 100
 	}
 	if chunkSize > 100000 {
 		chunkSize = 100000
@ -862,39 +765,10 @@ func (this *MigrationContext) ReadConfigFile() error {
 	if this.ConfigFile == "" {
 		return nil
 	}
-	cfg, err := ini.Load(this.ConfigFile)
-	if err != nil {
-		return err
-	}
-
-	if cfg.Section("client").HasKey("user") {
-		this.config.Client.User = cfg.Section("client").Key("user").String()
-	}
-
-	if cfg.Section("client").HasKey("password") {
-		this.config.Client.Password = cfg.Section("client").Key("password").String()
-	}
-
-	if cfg.Section("osc").HasKey("chunk_size") {
-		this.config.Osc.Chunk_Size, err = cfg.Section("osc").Key("chunk_size").Int64()
-		if err != nil {
-			return fmt.Errorf("Unable to read osc chunk size: %w", err)
-		}
-	}
-
-	if cfg.Section("osc").HasKey("max_load") {
-		this.config.Osc.Max_Load = cfg.Section("osc").Key("max_load").String()
-	}
-
-	if cfg.Section("osc").HasKey("replication_lag_query") {
-		this.config.Osc.Replication_Lag_Query = cfg.Section("osc").Key("replication_lag_query").String()
-	}
-
-	if cfg.Section("osc").HasKey("max_lag_millis") {
-		this.config.Osc.Max_Lag_Millis, err = cfg.Section("osc").Key("max_lag_millis").Int64()
-		if err != nil {
-			return fmt.Errorf("Unable to read max lag millis: %w", err)
-		}
+	gcfg.RelaxedParserMode = true
+	gcfgscanner.RelaxedScannerMode = true
+	if err := gcfg.ReadFileInto(&this.config, this.ConfigFile); err != nil {
+		return fmt.Errorf("Error reading config file %s. Details: %s", this.ConfigFile, err.Error())
 	}

 	// We accept user & password in the form "${SOME_ENV_VARIABLE}" in which case we pull
--- a/go/base/context_test.go
+++ b/go/base/context_test.go
@ -1,18 +1,16 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

 package base

 import (
-	"io/ioutil"
-	"os"
 	"testing"
 	"time"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
@ -58,65 +56,3 @@ func TestGetTableNames(t *testing.T) {
 		test.S(t).ExpectEquals(context.GetChangelogTableName(), "_tmp_ghc")
 	}
 }
-
-func TestReadConfigFile(t *testing.T) {
-	{
-		context := NewMigrationContext()
-		context.ConfigFile = "/does/not/exist"
-		if err := context.ReadConfigFile(); err == nil {
-			t.Fatal("Expected .ReadConfigFile() to return an error, got nil")
-		}
-	}
-	{
-		f, err := ioutil.TempFile("", t.Name())
-		if err != nil {
-			t.Fatalf("Failed to create tmp file: %v", err)
-		}
-		defer os.Remove(f.Name())
-
-		f.Write([]byte("[client]"))
-		context := NewMigrationContext()
-		context.ConfigFile = f.Name()
-		if err := context.ReadConfigFile(); err != nil {
-			t.Fatalf(".ReadConfigFile() failed: %v", err)
-		}
-	}
-	{
-		f, err := ioutil.TempFile("", t.Name())
-		if err != nil {
-			t.Fatalf("Failed to create tmp file: %v", err)
-		}
-		defer os.Remove(f.Name())
-
-		f.Write([]byte("[client]\nuser=test\npassword=123456"))
-		context := NewMigrationContext()
-		context.ConfigFile = f.Name()
-		if err := context.ReadConfigFile(); err != nil {
-			t.Fatalf(".ReadConfigFile() failed: %v", err)
-		}
-
-		if context.config.Client.User != "test" {
-			t.Fatalf("Expected client user %q, got %q", "test", context.config.Client.User)
-		} else if context.config.Client.Password != "123456" {
-			t.Fatalf("Expected client password %q, got %q", "123456", context.config.Client.Password)
-		}
-	}
-	{
-		f, err := ioutil.TempFile("", t.Name())
-		if err != nil {
-			t.Fatalf("Failed to create tmp file: %v", err)
-		}
-		defer os.Remove(f.Name())
-
-		f.Write([]byte("[osc]\nmax_load=10"))
-		context := NewMigrationContext()
-		context.ConfigFile = f.Name()
-		if err := context.ReadConfigFile(); err != nil {
-			t.Fatalf(".ReadConfigFile() failed: %v", err)
-		}
-
-		if context.config.Osc.Max_Load != "10" {
-			t.Fatalf("Expected osc 'max_load' %q, got %q", "10", context.config.Osc.Max_Load)
-		}
-	}
-}
--- a/go/base/default_logger.go
+++ b/go/base/default_logger.go
@ -1,12 +1,7 @@
-/*
-   Copyright 2022 GitHub Inc.
-         See https://github.com/github/gh-ost/blob/master/LICENSE
-*/
-
 package base

 import (
-	"github.com/openark/golib/log"
+	"github.com/outbrain/golib/log"
 )

 type simpleLogger struct{}
@ -17,18 +12,22 @@ func NewDefaultLogger() *simpleLogger {

 func (*simpleLogger) Debug(args ...interface{}) {
 	log.Debug(args[0].(string), args[1:])
+	return
 }

 func (*simpleLogger) Debugf(format string, args ...interface{}) {
 	log.Debugf(format, args...)
+	return
 }

 func (*simpleLogger) Info(args ...interface{}) {
 	log.Info(args[0].(string), args[1:])
+	return
 }

 func (*simpleLogger) Infof(format string, args ...interface{}) {
 	log.Infof(format, args...)
+	return
 }

 func (*simpleLogger) Warning(args ...interface{}) error {
@ -65,8 +64,10 @@ func (*simpleLogger) Fatale(err error) error {

 func (*simpleLogger) SetLevel(level log.LogLevel) {
 	log.SetLevel(level)
+	return
 }

 func (*simpleLogger) SetPrintStackTrace(printStackTraceFlag bool) {
 	log.SetPrintStackTrace(printStackTraceFlag)
+	return
 }
--- a/go/base/load_map_test.go
+++ b/go/base/load_map_test.go
@ -8,8 +8,8 @@ package base
 import (
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
--- a/go/base/utils.go
+++ b/go/base/utils.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -13,7 +13,6 @@ import (
 	"time"

 	gosql "database/sql"
-
 	"github.com/github/gh-ost/go/mysql"
 )

@ -25,7 +24,9 @@ func PrettifyDurationOutput(d time.Duration) string {
 	if d < time.Second {
 		return "0s"
 	}
-	return prettifyDurationRegexp.ReplaceAllString(d.String(), "")
+	result := fmt.Sprintf("%s", d)
+	result = prettifyDurationRegexp.ReplaceAllString(result, "")
+	return result
 }

 func FileExists(fileName string) bool {
@ -61,7 +62,7 @@ func StringContainsAll(s string, substrings ...string) bool {
 	return nonEmptyStringsFound
 }

-func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext, name string) (string, error) {
+func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext) (string, error) {
 	versionQuery := `select @@global.version`
 	var port, extraPort int
 	var version string
@ -69,13 +70,12 @@ func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig,
 		return "", err
 	}
 	extraPortQuery := `select @@global.extra_port`
-	if err := db.QueryRow(extraPortQuery).Scan(&extraPort); err != nil { // nolint:staticcheck
+	if err := db.QueryRow(extraPortQuery).Scan(&extraPort); err != nil {
 		// swallow this error. not all servers support extra_port
 	}
 	// AliyunRDS set users port to "NULL", replace it by gh-ost param
 	// GCP set users port to "NULL", replace it by gh-ost param
-	// Azure MySQL set users port to a different value by design, replace it by gh-ost para
-	if migrationContext.AliyunRDS || migrationContext.GoogleCloudPlatform || migrationContext.AzureMySQL {
+	if migrationContext.AliyunRDS || migrationContext.GoogleCloudPlatform {
 		port = connectionConfig.Key.Port
 	} else {
 		portQuery := `select @@global.port`
@ -85,7 +85,7 @@ func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig,
 	}

 	if connectionConfig.Key.Port == port || (extraPort > 0 && connectionConfig.Key.Port == extraPort) {
-		migrationContext.Log.Infof("%s connection validated on %+v", name, connectionConfig.Key)
+		migrationContext.Log.Infof("connection validated on %+v", connectionConfig.Key)
 		return version, nil
 	} else if extraPort == 0 {
 		return "", fmt.Errorf("Unexpected database port reported: %+v", port)
--- a/go/base/utils_test.go
+++ b/go/base/utils_test.go
@ -8,8 +8,8 @@ package base
 import (
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
--- a/go/binlog/gomysql_reader.go
+++ b/go/binlog/gomysql_reader.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -13,8 +13,8 @@ import (
 	"github.com/github/gh-ost/go/mysql"
 	"github.com/github/gh-ost/go/sql"

-	gomysql "github.com/go-mysql-org/go-mysql/mysql"
-	"github.com/go-mysql-org/go-mysql/replication"
+	gomysql "github.com/siddontang/go-mysql/mysql"
+	"github.com/siddontang/go-mysql/replication"
 	"golang.org/x/net/context"
 )

@ -28,25 +28,31 @@ type GoMySQLReader struct {
 	LastAppliedRowsEventHint mysql.BinlogCoordinates
 }

-func NewGoMySQLReader(migrationContext *base.MigrationContext) *GoMySQLReader {
-	connectionConfig := migrationContext.InspectorConnectionConfig
-	return &GoMySQLReader{
+func NewGoMySQLReader(migrationContext *base.MigrationContext) (binlogReader *GoMySQLReader, err error) {
+	binlogReader = &GoMySQLReader{
 		migrationContext:        migrationContext,
-		connectionConfig:        connectionConfig,
+		connectionConfig:        migrationContext.InspectorConnectionConfig,
 		currentCoordinates:      mysql.BinlogCoordinates{},
 		currentCoordinatesMutex: &sync.Mutex{},
-		binlogSyncer: replication.NewBinlogSyncer(replication.BinlogSyncerConfig{
-			ServerID:             uint32(migrationContext.ReplicaServerId),
-			Flavor:               gomysql.MySQLFlavor,
-			Host:                 connectionConfig.Key.Hostname,
-			Port:                 uint16(connectionConfig.Key.Port),
-			User:                 connectionConfig.User,
-			Password:             connectionConfig.Password,
-			TLSConfig:            connectionConfig.TLSConfig(),
-			UseDecimal:           true,
-			MaxReconnectAttempts: migrationContext.BinlogSyncerMaxReconnectAttempts,
-		}),
+		binlogSyncer:            nil,
+		binlogStreamer:          nil,
 	}
+
+	serverId := uint32(migrationContext.ReplicaServerId)
+
+	binlogSyncerConfig := replication.BinlogSyncerConfig{
+		ServerID:   serverId,
+		Flavor:     "mysql",
+		Host:       binlogReader.connectionConfig.Key.Hostname,
+		Port:       uint16(binlogReader.connectionConfig.Key.Port),
+		User:       binlogReader.connectionConfig.User,
+		Password:   binlogReader.connectionConfig.Password,
+		TLSConfig:  binlogReader.connectionConfig.TLSConfig(),
+		UseDecimal: true,
+	}
+	binlogReader.binlogSyncer = replication.NewBinlogSyncer(binlogSyncerConfig)
+
+	return binlogReader, err
 }

 // ConnectBinlogStreamer
@ -58,10 +64,7 @@ func (this *GoMySQLReader) ConnectBinlogStreamer(coordinates mysql.BinlogCoordin
 	this.currentCoordinates = coordinates
 	this.migrationContext.Log.Infof("Connecting binlog streamer at %+v", this.currentCoordinates)
 	// Start sync with specified binlog file and position
-	this.binlogStreamer, err = this.binlogSyncer.StartSync(gomysql.Position{
-		Name: this.currentCoordinates.LogFile,
-		Pos:  uint32(this.currentCoordinates.LogPos),
-	})
+	this.binlogStreamer, err = this.binlogSyncer.StartSync(gomysql.Position{this.currentCoordinates.LogFile, uint32(this.currentCoordinates.LogPos)})

 	return err
 }
@ -139,17 +142,15 @@ func (this *GoMySQLReader) StreamEvents(canStopStreaming func() bool, entriesCha
 			defer this.currentCoordinatesMutex.Unlock()
 			this.currentCoordinates.LogPos = int64(ev.Header.LogPos)
 		}()
-
-		switch binlogEvent := ev.Event.(type) {
-		case *replication.RotateEvent:
+		if rotateEvent, ok := ev.Event.(*replication.RotateEvent); ok {
 			func() {
 				this.currentCoordinatesMutex.Lock()
 				defer this.currentCoordinatesMutex.Unlock()
-				this.currentCoordinates.LogFile = string(binlogEvent.NextLogName)
+				this.currentCoordinates.LogFile = string(rotateEvent.NextLogName)
 			}()
-			this.migrationContext.Log.Infof("rotate to next log from %s:%d to %s", this.currentCoordinates.LogFile, int64(ev.Header.LogPos), binlogEvent.NextLogName)
-		case *replication.RowsEvent:
-			if err := this.handleRowsEvent(ev, binlogEvent, entriesChannel); err != nil {
+			this.migrationContext.Log.Infof("rotate to next log from %s:%d to %s", this.currentCoordinates.LogFile, int64(ev.Header.LogPos), rotateEvent.NextLogName)
+		} else if rowsEvent, ok := ev.Event.(*replication.RowsEvent); ok {
+			if err := this.handleRowsEvent(ev, rowsEvent, entriesChannel); err != nil {
 				return err
 			}
 		}
--- a/go/cmd/gh-ost/main.go
+++ b/go/cmd/gh-ost/main.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -8,7 +8,6 @@ package main
 import (
 	"flag"
 	"fmt"
-	"net/url"
 	"os"
 	"os/signal"
 	"syscall"
@ -17,9 +16,9 @@ import (
 	"github.com/github/gh-ost/go/logic"
 	"github.com/github/gh-ost/go/sql"
 	_ "github.com/go-sql-driver/mysql"
-	"github.com/openark/golib/log"
+	"github.com/outbrain/golib/log"

-	"golang.org/x/term"
+	"golang.org/x/crypto/ssh/terminal"
 )

 var AppVersion string
@ -67,9 +66,6 @@ func main() {
 	flag.StringVar(&migrationContext.DatabaseName, "database", "", "database name (mandatory)")
 	flag.StringVar(&migrationContext.OriginalTableName, "table", "", "table name (mandatory)")
 	flag.StringVar(&migrationContext.AlterStatement, "alter", "", "alter statement (mandatory)")
-	flag.BoolVar(&migrationContext.AttemptInstantDDL, "attempt-instant-ddl", false, "Attempt to use instant DDL for this migration first")
-	storageEngine := flag.String("storage-engine", "innodb", "Specify table storage engine (default: 'innodb'). When 'rocksdb': the session transaction isolation level is changed from REPEATABLE_READ to READ_COMMITTED.")
-
 	flag.BoolVar(&migrationContext.CountTableRows, "exact-rowcount", false, "actually count table rows as opposed to estimate them (results in more accurate progress estimation)")
 	flag.BoolVar(&migrationContext.ConcurrentCountTableRows, "concurrent-rowcount", true, "(with --exact-rowcount), when true (default): count rows after row-copy begins, concurrently, and adjust row estimate later on; when false: first count rows, then start row copy")
 	flag.BoolVar(&migrationContext.AllowedRunningOnMaster, "allow-on-master", false, "allow this migration to run directly on master. Preferably it would run on a replica")
@ -81,10 +77,8 @@ func main() {
 	flag.BoolVar(&migrationContext.DiscardForeignKeys, "discard-foreign-keys", false, "DANGER! This flag will migrate a table that has foreign keys and will NOT create foreign keys on the ghost table, thus your altered table will have NO foreign keys. This is useful for intentional dropping of foreign keys")
 	flag.BoolVar(&migrationContext.SkipForeignKeyChecks, "skip-foreign-key-checks", false, "set to 'true' when you know for certain there are no foreign keys on your table, and wish to skip the time it takes for gh-ost to verify that")
 	flag.BoolVar(&migrationContext.SkipStrictMode, "skip-strict-mode", false, "explicitly tell gh-ost binlog applier not to enforce strict sql mode")
-	flag.BoolVar(&migrationContext.AllowZeroInDate, "allow-zero-in-date", false, "explicitly tell gh-ost binlog applier to ignore NO_ZERO_IN_DATE,NO_ZERO_DATE in sql_mode")
 	flag.BoolVar(&migrationContext.AliyunRDS, "aliyun-rds", false, "set to 'true' when you execute on Aliyun RDS.")
 	flag.BoolVar(&migrationContext.GoogleCloudPlatform, "gcp", false, "set to 'true' when you execute on a 1st generation Google Cloud Platform (GCP).")
-	flag.BoolVar(&migrationContext.AzureMySQL, "azure", false, "set to 'true' when you execute on Azure Database on MySQL.")

 	executeFlag := flag.Bool("execute", false, "actually execute the alter & migrate the table. Default is noop: do some tests and exit")
 	flag.BoolVar(&migrationContext.TestOnReplica, "test-on-replica", false, "Have the migration run on a replica, not on the master. At the end of migration replication is stopped, and tables are swapped and immediately swap-revert. Replication remains stopped and you can compare the two tables for building trust")
@ -103,7 +97,7 @@ func main() {
 	flag.BoolVar(&migrationContext.AssumeRBR, "assume-rbr", false, "set to 'true' when you know for certain your server uses 'ROW' binlog_format. gh-ost is unable to tell, event after reading binlog_format, whether the replication process does indeed use 'ROW', and restarts replication to be certain RBR setting is applied. Such operation requires SUPER privileges which you might not have. Setting this flag avoids restarting replication and you can proceed to use gh-ost without SUPER privileges")
 	flag.BoolVar(&migrationContext.CutOverExponentialBackoff, "cut-over-exponential-backoff", false, "Wait exponentially longer intervals between failed cut-over attempts. Wait intervals obey a maximum configurable with 'exponential-backoff-max-interval').")
 	exponentialBackoffMaxInterval := flag.Int64("exponential-backoff-max-interval", 64, "Maximum number of seconds to wait between attempts when performing various operations with exponential backoff.")
-	chunkSize := flag.Int64("chunk-size", 1000, "amount of rows to handle in each iteration (allowed range: 10-100,000)")
+	chunkSize := flag.Int64("chunk-size", 1000, "amount of rows to handle in each iteration (allowed range: 100-100,000)")
 	dmlBatchSize := flag.Int64("dml-batch-size", 10, "batch size for DML events to apply in a single transaction (range 1-100)")
 	defaultRetries := flag.Int64("default-retries", 60, "Default number of retries for various operations before panicking")
 	cutOverLockTimeoutSeconds := flag.Int64("cut-over-lock-timeout-seconds", 3, "Max number of seconds to hold locks on tables while attempting to cut-over (retry attempted when lock exceeds timeout)")
@ -114,8 +108,6 @@ func main() {
 	throttleControlReplicas := flag.String("throttle-control-replicas", "", "List of replicas on which to check for lag; comma delimited. Example: myhost1.com:3306,myhost2.com,myhost3.com:3307")
 	throttleQuery := flag.String("throttle-query", "", "when given, issued (every second) to check if operation should throttle. Expecting to return zero for no-throttle, >0 for throttle. Query is issued on the migrated server. Make sure this query is lightweight")
 	throttleHTTP := flag.String("throttle-http", "", "when given, gh-ost checks given URL via HEAD request; any response code other than 200 (OK) causes throttling; make sure it has low latency response")
-	flag.Int64Var(&migrationContext.ThrottleHTTPIntervalMillis, "throttle-http-interval-millis", 100, "Number of milliseconds to wait before triggering another HTTP throttle check")
-	flag.Int64Var(&migrationContext.ThrottleHTTPTimeoutMillis, "throttle-http-timeout-millis", 1000, "Number of milliseconds to use as an HTTP throttle check timeout")
 	ignoreHTTPErrors := flag.Bool("ignore-http-errors", false, "ignore HTTP connection errors during throttle check")
 	heartbeatIntervalMillis := flag.Int64("heartbeat-interval-millis", 100, "how frequently would gh-ost inject a heartbeat value")
 	flag.StringVar(&migrationContext.ThrottleFlagFile, "throttle-flag-file", "", "operation pauses when this file exists; hint: use a file that is specific to the table being altered")
@ -131,15 +123,13 @@ func main() {
 	flag.StringVar(&migrationContext.HooksHintMessage, "hooks-hint", "", "arbitrary message to be injected to hooks via GH_OST_HOOKS_HINT, for your convenience")
 	flag.StringVar(&migrationContext.HooksHintOwner, "hooks-hint-owner", "", "arbitrary name of owner to be injected to hooks via GH_OST_HOOKS_HINT_OWNER, for your convenience")
 	flag.StringVar(&migrationContext.HooksHintToken, "hooks-hint-token", "", "arbitrary token to be injected to hooks via GH_OST_HOOKS_HINT_TOKEN, for your convenience")
-	flag.Int64Var(&migrationContext.HooksStatusIntervalSec, "hooks-status-interval", 60, "how many seconds to wait between calling onStatus hook")

 	flag.UintVar(&migrationContext.ReplicaServerId, "replica-server-id", 99999, "server id used by gh-ost process. Default: 99999")
-	flag.IntVar(&migrationContext.BinlogSyncerMaxReconnectAttempts, "binlogsyncer-max-reconnect-attempts", 0, "when master node fails, the maximum number of binlog synchronization attempts to reconnect. 0 is unlimited")

 	maxLoad := flag.String("max-load", "", "Comma delimited status-name=threshold. e.g: 'Threads_running=100,Threads_connected=500'. When status exceeds threshold, app throttles writes")
 	criticalLoad := flag.String("critical-load", "", "Comma delimited status-name=threshold, same format as --max-load. When status exceeds threshold, app panics and quits")
 	flag.Int64Var(&migrationContext.CriticalLoadIntervalMilliseconds, "critical-load-interval-millis", 0, "When 0, migration immediately bails out upon meeting critical-load. When non-zero, a second check is done after given interval, and migration only bails out if 2nd check still meets critical load")
-	flag.Int64Var(&migrationContext.CriticalLoadHibernateSeconds, "critical-load-hibernate-seconds", 0, "When non-zero, critical-load does not panic and bail out; instead, gh-ost goes into hibernation for the specified duration. It will not read/write anything from/to any server")
+	flag.Int64Var(&migrationContext.CriticalLoadHibernateSeconds, "critical-load-hibernate-seconds", 0, "When nonzero, critical-load does not panic and bail out; instead, gh-ost goes into hibernate for the specified duration. It will not read/write anything to from/to any server")
 	quiet := flag.Bool("quiet", false, "quiet")
 	verbose := flag.Bool("verbose", false, "verbose")
 	debug := flag.Bool("debug", false, "debug mode (very verbose)")
@ -184,12 +174,8 @@ func main() {
 		migrationContext.Log.SetLevel(log.ERROR)
 	}

-	if err := migrationContext.SetConnectionConfig(*storageEngine); err != nil {
-		migrationContext.Log.Fatale(err)
-	}
-
 	if migrationContext.AlterStatement == "" {
-		log.Fatal("--alter must be provided and statement must not be empty")
+		log.Fatalf("--alter must be provided and statement must not be empty")
 	}
 	parser := sql.NewParserFromAlterStatement(migrationContext.AlterStatement)
 	migrationContext.AlterStatementOptions = parser.GetAlterStatementOptions()
@ -198,63 +184,55 @@ func main() {
 		if parser.HasExplicitSchema() {
 			migrationContext.DatabaseName = parser.GetExplicitSchema()
 		} else {
-			log.Fatal("--database must be provided and database name must not be empty, or --alter must specify database name")
+			log.Fatalf("--database must be provided and database name must not be empty, or --alter must specify database name")
 		}
 	}
-
-	if err := flag.Set("database", url.QueryEscape(migrationContext.DatabaseName)); err != nil {
-		migrationContext.Log.Fatale(err)
-	}
-
 	if migrationContext.OriginalTableName == "" {
 		if parser.HasExplicitTable() {
 			migrationContext.OriginalTableName = parser.GetExplicitTable()
 		} else {
-			log.Fatal("--table must be provided and table name must not be empty, or --alter must specify table name")
+			log.Fatalf("--table must be provided and table name must not be empty, or --alter must specify table name")
 		}
 	}
 	migrationContext.Noop = !(*executeFlag)
 	if migrationContext.AllowedRunningOnMaster && migrationContext.TestOnReplica {
-		migrationContext.Log.Fatal("--allow-on-master and --test-on-replica are mutually exclusive")
+		migrationContext.Log.Fatalf("--allow-on-master and --test-on-replica are mutually exclusive")
 	}
 	if migrationContext.AllowedRunningOnMaster && migrationContext.MigrateOnReplica {
-		migrationContext.Log.Fatal("--allow-on-master and --migrate-on-replica are mutually exclusive")
+		migrationContext.Log.Fatalf("--allow-on-master and --migrate-on-replica are mutually exclusive")
 	}
 	if migrationContext.MigrateOnReplica && migrationContext.TestOnReplica {
-		migrationContext.Log.Fatal("--migrate-on-replica and --test-on-replica are mutually exclusive")
+		migrationContext.Log.Fatalf("--migrate-on-replica and --test-on-replica are mutually exclusive")
 	}
 	if migrationContext.SwitchToRowBinlogFormat && migrationContext.AssumeRBR {
-		migrationContext.Log.Fatal("--switch-to-rbr and --assume-rbr are mutually exclusive")
+		migrationContext.Log.Fatalf("--switch-to-rbr and --assume-rbr are mutually exclusive")
 	}
 	if migrationContext.TestOnReplicaSkipReplicaStop {
 		if !migrationContext.TestOnReplica {
-			migrationContext.Log.Fatal("--test-on-replica-skip-replica-stop requires --test-on-replica to be enabled")
+			migrationContext.Log.Fatalf("--test-on-replica-skip-replica-stop requires --test-on-replica to be enabled")
 		}
 		migrationContext.Log.Warning("--test-on-replica-skip-replica-stop enabled. We will not stop replication before cut-over. Ensure you have a plugin that does this.")
 	}
 	if migrationContext.CliMasterUser != "" && migrationContext.AssumeMasterHostname == "" {
-		migrationContext.Log.Fatal("--master-user requires --assume-master-host")
+		migrationContext.Log.Fatalf("--master-user requires --assume-master-host")
 	}
 	if migrationContext.CliMasterPassword != "" && migrationContext.AssumeMasterHostname == "" {
-		migrationContext.Log.Fatal("--master-password requires --assume-master-host")
+		migrationContext.Log.Fatalf("--master-password requires --assume-master-host")
 	}
 	if migrationContext.TLSCACertificate != "" && !migrationContext.UseTLS {
-		migrationContext.Log.Fatal("--ssl-ca requires --ssl")
+		migrationContext.Log.Fatalf("--ssl-ca requires --ssl")
 	}
 	if migrationContext.TLSCertificate != "" && !migrationContext.UseTLS {
-		migrationContext.Log.Fatal("--ssl-cert requires --ssl")
+		migrationContext.Log.Fatalf("--ssl-cert requires --ssl")
 	}
 	if migrationContext.TLSKey != "" && !migrationContext.UseTLS {
-		migrationContext.Log.Fatal("--ssl-key requires --ssl")
+		migrationContext.Log.Fatalf("--ssl-key requires --ssl")
 	}
 	if migrationContext.TLSAllowInsecure && !migrationContext.UseTLS {
-		migrationContext.Log.Fatal("--ssl-allow-insecure requires --ssl")
+		migrationContext.Log.Fatalf("--ssl-allow-insecure requires --ssl")
 	}
 	if *replicationLagQuery != "" {
-		migrationContext.Log.Warning("--replication-lag-query is deprecated")
-	}
-	if *storageEngine == "rocksdb" {
-		migrationContext.Log.Warning("RocksDB storage engine support is experimental")
+		migrationContext.Log.Warningf("--replication-lag-query is deprecated")
 	}

 	switch *cutOver {
@ -282,7 +260,7 @@ func main() {
 	}
 	if *askPass {
 		fmt.Println("Password:")
-		bytePassword, err := term.ReadPassword(syscall.Stdin)
+		bytePassword, err := terminal.ReadPassword(int(syscall.Stdin))
 		if err != nil {
 			migrationContext.Log.Fatale(err)
 		}
@ -311,10 +289,11 @@ func main() {
 	log.Infof("starting gh-ost %+v", AppVersion)
 	acceptSignals(migrationContext)

-	migrator := logic.NewMigrator(migrationContext, AppVersion)
-	if err := migrator.Migrate(); err != nil {
+	migrator := logic.NewMigrator(migrationContext)
+	err := migrator.Migrate()
+	if err != nil {
 		migrator.ExecOnFailureHook()
 		migrationContext.Log.Fatale(err)
 	}
-	fmt.Fprintln(os.Stdout, "# Done")
+	fmt.Fprintf(os.Stdout, "# Done\n")
 }
--- a/go/logic/applier.go
+++ b/go/logic/applier.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -8,7 +8,6 @@ package logic
 import (
 	gosql "database/sql"
 	"fmt"
-	"strings"
 	"sync/atomic"
 	"time"

@ -17,13 +16,12 @@ import (
 	"github.com/github/gh-ost/go/mysql"
 	"github.com/github/gh-ost/go/sql"

-	"github.com/openark/golib/log"
-	"github.com/openark/golib/sqlutils"
+	"github.com/outbrain/golib/sqlutils"
+	"sync"
 )

 const (
-	GhostChangelogTableComment = "gh-ost changelog"
-	atomicCutOverMagicHint     = "ghost-cut-over-sentry"
+	atomicCutOverMagicHint = "ghost-cut-over-sentry"
 )

 type dmlBuildResult struct {
@ -48,7 +46,7 @@ func newDmlBuildResultError(err error) *dmlBuildResult {
 	}
 }

-// Applier connects and writes the applier-server, which is the server where migration
+// Applier connects and writes the the applier-server, which is the server where migration
 // happens. This is typically the master, but could be a replica when `--test-on-replica` or
 // `--execute-on-replica` are given.
 // Applier is the one to actually write row data and apply binlog events onto the ghost table.
@ -59,7 +57,6 @@ type Applier struct {
 	singletonDB       *gosql.DB
 	migrationContext  *base.MigrationContext
 	finishedMigrating int64
-	name              string
 }

 func NewApplier(migrationContext *base.MigrationContext) *Applier {
@ -67,11 +64,11 @@ func NewApplier(migrationContext *base.MigrationContext) *Applier {
 		connectionConfig:  migrationContext.ApplierConnectionConfig,
 		migrationContext:  migrationContext,
 		finishedMigrating: 0,
-		name:              "applier",
 	}
 }

 func (this *Applier) InitDBConnections() (err error) {
+
 	applierUri := this.connectionConfig.GetDBUri(this.migrationContext.DatabaseName)
 	if this.db, _, err = mysql.GetDB(this.migrationContext.Uuid, applierUri); err != nil {
 		return err
@ -81,18 +78,18 @@ func (this *Applier) InitDBConnections() (err error) {
 		return err
 	}
 	this.singletonDB.SetMaxOpenConns(1)
-	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name)
+	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext)
 	if err != nil {
 		return err
 	}
-	if _, err := base.ValidateConnection(this.singletonDB, this.connectionConfig, this.migrationContext, this.name); err != nil {
+	if _, err := base.ValidateConnection(this.singletonDB, this.connectionConfig, this.migrationContext); err != nil {
 		return err
 	}
 	this.migrationContext.ApplierMySQLVersion = version
 	if err := this.validateAndReadTimeZone(); err != nil {
 		return err
 	}
-	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform && !this.migrationContext.AzureMySQL {
+	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform {
 		if impliedKey, err := mysql.GetInstanceKey(this.db); err != nil {
 			return err
 		} else {
@ -117,33 +114,6 @@ func (this *Applier) validateAndReadTimeZone() error {
 	return nil
 }

-// generateSqlModeQuery return a `sql_mode = ...` query, to be wrapped with a `set session` or `set global`,
-// based on gh-ost configuration:
-// - User may skip strict mode
-// - User may allow zero dats or zero in dates
-func (this *Applier) generateSqlModeQuery() string {
-	sqlModeAddendum := []string{`NO_AUTO_VALUE_ON_ZERO`}
-	if !this.migrationContext.SkipStrictMode {
-		sqlModeAddendum = append(sqlModeAddendum, `STRICT_ALL_TABLES`)
-	}
-	sqlModeQuery := fmt.Sprintf("CONCAT(@@session.sql_mode, ',%s')", strings.Join(sqlModeAddendum, ","))
-	if this.migrationContext.AllowZeroInDate {
-		sqlModeQuery = fmt.Sprintf("REPLACE(REPLACE(%s, 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', '')", sqlModeQuery)
-	}
-
-	return fmt.Sprintf("sql_mode = %s", sqlModeQuery)
-}
-
-// generateInstantDDLQuery returns the SQL for this ALTER operation
-// with an INSTANT assertion (requires MySQL 8.0+)
-func (this *Applier) generateInstantDDLQuery() string {
-	return fmt.Sprintf(`ALTER /* gh-ost */ TABLE %s.%s %s, ALGORITHM=INSTANT`,
-		sql.EscapeName(this.migrationContext.DatabaseName),
-		sql.EscapeName(this.migrationContext.OriginalTableName),
-		this.migrationContext.AlterStatementOptions,
-	)
-}
-
 // readTableColumns reads table columns on applier
 func (this *Applier) readTableColumns() (err error) {
 	this.migrationContext.Log.Infof("Examining table structure on applier")
@ -197,27 +167,6 @@ func (this *Applier) ValidateOrDropExistingTables() error {
 	return nil
 }

-// AttemptInstantDDL attempts to use instant DDL (from MySQL 8.0, and earlier in Aurora and some others).
-// If successful, the operation is only a meta-data change so a lot of time is saved!
-// The risk of attempting to instant DDL when not supported is that a metadata lock may be acquired.
-// This is minor, since gh-ost will eventually require a metadata lock anyway, but at the cut-over stage.
-// Instant operations include:
-// - Adding a column
-// - Dropping a column
-// - Dropping an index
-// - Extending a VARCHAR column
-// - Adding a virtual generated column
-// It is not reliable to parse the `alter` statement to determine if it is instant or not.
-// This is because the table might be in an older row format, or have some other incompatibility
-// that is difficult to identify.
-func (this *Applier) AttemptInstantDDL() error {
-	query := this.generateInstantDDLQuery()
-	this.migrationContext.Log.Infof("INSTANT DDL query is: %s", query)
-	// We don't need a trx, because for instant DDL the SQL mode doesn't matter.
-	_, err := this.db.Exec(query)
-	return err
-}
-
 // CreateGhostTable creates the ghost table on the applier host
 func (this *Applier) CreateGhostTable() error {
 	query := fmt.Sprintf(`create /* gh-ost */ table %s.%s like %s.%s`,
@ -230,33 +179,11 @@ func (this *Applier) CreateGhostTable() error {
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(this.migrationContext.GetGhostTableName()),
 	)
-
-	err := func() error {
-		tx, err := this.db.Begin()
-		if err != nil {
-			return err
-		}
-		defer tx.Rollback()
-
-		sessionQuery := fmt.Sprintf(`SET SESSION time_zone = '%s'`, this.migrationContext.ApplierTimeZone)
-		sessionQuery = fmt.Sprintf("%s, %s", sessionQuery, this.generateSqlModeQuery())
-
-		if _, err := tx.Exec(sessionQuery); err != nil {
-			return err
-		}
-		if _, err := tx.Exec(query); err != nil {
-			return err
-		}
-		this.migrationContext.Log.Infof("Ghost table created")
-		if err := tx.Commit(); err != nil {
-			// Neither SET SESSION nor ALTER are really transactional, so strictly speaking
-			// there's no need to commit; but let's do this the legit way anyway.
-			return err
-		}
-		return nil
-	}()
-
-	return err
+	if _, err := sqlutils.ExecNoPrepare(this.db, query); err != nil {
+		return err
+	}
+	this.migrationContext.Log.Infof("Ghost table created")
+	return nil
 }

 // AlterGhost applies `alter` statement on ghost table
@ -271,51 +198,10 @@ func (this *Applier) AlterGhost() error {
 		sql.EscapeName(this.migrationContext.GetGhostTableName()),
 	)
 	this.migrationContext.Log.Debugf("ALTER statement: %s", query)
-
-	err := func() error {
-		tx, err := this.db.Begin()
-		if err != nil {
-			return err
-		}
-		defer tx.Rollback()
-
-		sessionQuery := fmt.Sprintf(`SET SESSION time_zone = '%s'`, this.migrationContext.ApplierTimeZone)
-		sessionQuery = fmt.Sprintf("%s, %s", sessionQuery, this.generateSqlModeQuery())
-
-		if _, err := tx.Exec(sessionQuery); err != nil {
-			return err
-		}
-		if _, err := tx.Exec(query); err != nil {
-			return err
-		}
-		this.migrationContext.Log.Infof("Ghost table altered")
-		if err := tx.Commit(); err != nil {
-			// Neither SET SESSION nor ALTER are really transactional, so strictly speaking
-			// there's no need to commit; but let's do this the legit way anyway.
-			return err
-		}
-		return nil
-	}()
-
-	return err
-}
-
-// AlterGhost applies `alter` statement on ghost table
-func (this *Applier) AlterGhostAutoIncrement() error {
-	query := fmt.Sprintf(`alter /* gh-ost */ table %s.%s AUTO_INCREMENT=%d`,
-		sql.EscapeName(this.migrationContext.DatabaseName),
-		sql.EscapeName(this.migrationContext.GetGhostTableName()),
-		this.migrationContext.OriginalTableAutoIncrement,
-	)
-	this.migrationContext.Log.Infof("Altering ghost table AUTO_INCREMENT value %s.%s",
-		sql.EscapeName(this.migrationContext.DatabaseName),
-		sql.EscapeName(this.migrationContext.GetGhostTableName()),
-	)
-	this.migrationContext.Log.Debugf("AUTO_INCREMENT ALTER statement: %s", query)
 	if _, err := sqlutils.ExecNoPrepare(this.db, query); err != nil {
 		return err
 	}
-	this.migrationContext.Log.Infof("Ghost table AUTO_INCREMENT altered")
+	this.migrationContext.Log.Infof("Ghost table altered")
 	return nil
 }

@ -325,16 +211,16 @@ func (this *Applier) CreateChangelogTable() error {
 		return err
 	}
 	query := fmt.Sprintf(`create /* gh-ost */ table %s.%s (
-			id bigint unsigned auto_increment,
+			id bigint auto_increment,
 			last_update timestamp not null DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 			hint varchar(64) charset ascii not null,
 			value varchar(4096) charset ascii not null,
 			primary key(id),
 			unique key hint_uidx(hint)
-		) auto_increment=256 comment='%s'`,
+		) auto_increment=256
+		`,
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(this.migrationContext.GetChangelogTableName()),
-		GhostChangelogTableComment,
 	)
 	this.migrationContext.Log.Infof("Creating changelog table %s.%s",
 		sql.EscapeName(this.migrationContext.DatabaseName),
@ -436,9 +322,8 @@ func (this *Applier) InitiateHeartbeat() {
 	}
 	injectHeartbeat()

-	ticker := time.NewTicker(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
-	defer ticker.Stop()
-	for range ticker.C {
+	heartbeatTick := time.Tick(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
+	for range heartbeatTick {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 			return
 		}
@ -468,20 +353,17 @@ func (this *Applier) ExecuteThrottleQuery() (int64, error) {
 	return result, nil
 }

-// readMigrationMinValues returns the minimum values to be iterated on rowcopy
-func (this *Applier) readMigrationMinValues(tx *gosql.Tx, uniqueKey *sql.UniqueKey) error {
+// ReadMigrationMinValues returns the minimum values to be iterated on rowcopy
+func (this *Applier) ReadMigrationMinValues(uniqueKey *sql.UniqueKey) error {
 	this.migrationContext.Log.Debugf("Reading migration range according to key: %s", uniqueKey.Name)
 	query, err := sql.BuildUniqueKeyMinValuesPreparedQuery(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, &uniqueKey.Columns)
 	if err != nil {
 		return err
 	}
-
-	rows, err := tx.Query(query)
+	rows, err := this.db.Query(query)
 	if err != nil {
 		return err
 	}
-	defer rows.Close()
-
 	for rows.Next() {
 		this.migrationContext.MigrationRangeMinValues = sql.NewColumnValues(uniqueKey.Len())
 		if err = rows.Scan(this.migrationContext.MigrationRangeMinValues.ValuesPointers...); err != nil {
@ -490,23 +372,21 @@ func (this *Applier) readMigrationMinValues(tx *gosql.Tx, uniqueKey *sql.UniqueK
 	}
 	this.migrationContext.Log.Infof("Migration min values: [%s]", this.migrationContext.MigrationRangeMinValues)

-	return rows.Err()
+	err = rows.Err()
+	return err
 }

-// readMigrationMaxValues returns the maximum values to be iterated on rowcopy
-func (this *Applier) readMigrationMaxValues(tx *gosql.Tx, uniqueKey *sql.UniqueKey) error {
+// ReadMigrationMaxValues returns the maximum values to be iterated on rowcopy
+func (this *Applier) ReadMigrationMaxValues(uniqueKey *sql.UniqueKey) error {
 	this.migrationContext.Log.Debugf("Reading migration range according to key: %s", uniqueKey.Name)
 	query, err := sql.BuildUniqueKeyMaxValuesPreparedQuery(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, &uniqueKey.Columns)
 	if err != nil {
 		return err
 	}
-
-	rows, err := tx.Query(query)
+	rows, err := this.db.Query(query)
 	if err != nil {
 		return err
 	}
-	defer rows.Close()
-
 	for rows.Next() {
 		this.migrationContext.MigrationRangeMaxValues = sql.NewColumnValues(uniqueKey.Len())
 		if err = rows.Scan(this.migrationContext.MigrationRangeMaxValues.ValuesPointers...); err != nil {
@ -515,45 +395,19 @@ func (this *Applier) readMigrationMaxValues(tx *gosql.Tx, uniqueKey *sql.UniqueK
 	}
 	this.migrationContext.Log.Infof("Migration max values: [%s]", this.migrationContext.MigrationRangeMaxValues)

-	return rows.Err()
+	err = rows.Err()
+	return err
 }

-// ReadMigrationRangeValues reads min/max values that will be used for rowcopy.
-// Before read min/max, write a changelog state into the ghc table to avoid lost data in mysql two-phase commit.
-/*
-Detail description of the lost data in mysql two-phase commit issue by @Fanduzi:
-	When using semi-sync and setting rpl_semi_sync_master_wait_point=AFTER_SYNC,
-	if an INSERT statement is being committed but blocks due to an unmet ack count,
-	the data inserted by the transaction is not visible to ReadMigrationRangeValues,
-	so the copy of the existing data in the table does not include the new row inserted by the transaction.
-	However, the binlog event for the transaction is already written to the binlog,
-	so the addDMLEventsListener only captures the binlog event after the transaction,
-	and thus the transaction's binlog event is not captured, resulting in data loss.
-
-	If write a changelog into ghc table before ReadMigrationRangeValues, and the transaction commit blocks
-	because the ack is not met, then the changelog will not be able to write, so the ReadMigrationRangeValues
-	will not be run. When the changelog writes successfully, the ReadMigrationRangeValues will read the
-	newly inserted data, thus Avoiding data loss due to the above problem.
-*/
+// ReadMigrationRangeValues reads min/max values that will be used for rowcopy
 func (this *Applier) ReadMigrationRangeValues() error {
-	if _, err := this.WriteChangelogState(string(ReadMigrationRangeValues)); err != nil {
+	if err := this.ReadMigrationMinValues(this.migrationContext.UniqueKey); err != nil {
 		return err
 	}
-
-	tx, err := this.db.Begin()
-	if err != nil {
+	if err := this.ReadMigrationMaxValues(this.migrationContext.UniqueKey); err != nil {
 		return err
 	}
-	defer tx.Rollback()
-
-	if err := this.readMigrationMinValues(tx, this.migrationContext.UniqueKey); err != nil {
-		return err
-	}
-	if err := this.readMigrationMaxValues(tx, this.migrationContext.UniqueKey); err != nil {
-		return err
-	}
-
-	return tx.Commit()
+	return nil
 }

 // CalculateNextIterationRangeEndValues reads the next-iteration-range-end unique key values,
@ -583,13 +437,10 @@ func (this *Applier) CalculateNextIterationRangeEndValues() (hasFurtherRange boo
 		if err != nil {
 			return hasFurtherRange, err
 		}
-
 		rows, err := this.db.Query(query, explodedArgs...)
 		if err != nil {
 			return hasFurtherRange, err
 		}
-		defer rows.Close()
-
 		iterationRangeMaxValues := sql.NewColumnValues(this.migrationContext.UniqueKey.Len())
 		for rows.Next() {
 			if err = rows.Scan(iterationRangeMaxValues.ValuesPointers...); err != nil {
@ -638,9 +489,12 @@ func (this *Applier) ApplyIterationInsertQuery() (chunkSize int64, rowsAffected
 			return nil, err
 		}
 		defer tx.Rollback()
-
 		sessionQuery := fmt.Sprintf(`SET SESSION time_zone = '%s'`, this.migrationContext.ApplierTimeZone)
-		sessionQuery = fmt.Sprintf("%s, %s", sessionQuery, this.generateSqlModeQuery())
+		sqlModeAddendum := `,NO_AUTO_VALUE_ON_ZERO`
+		if !this.migrationContext.SkipStrictMode {
+			sqlModeAddendum = fmt.Sprintf("%s,STRICT_ALL_TABLES", sqlModeAddendum)
+		}
+		sessionQuery = fmt.Sprintf("%s, sql_mode = CONCAT(@@session.sql_mode, ',%s')", sessionQuery, sqlModeAddendum)

 		if _, err := tx.Exec(sessionQuery); err != nil {
 			return nil, err
@ -934,7 +788,7 @@ func (this *Applier) CreateAtomicCutOverSentryTable() error {
 }

 // AtomicCutOverMagicLock
-func (this *Applier) AtomicCutOverMagicLock(sessionIdChan chan int64, tableLocked chan<- error, okToUnlockTable <-chan bool, tableUnlocked chan<- error) error {
+func (this *Applier) AtomicCutOverMagicLock(sessionIdChan chan int64, tableLocked chan<- error, okToUnlockTable <-chan bool, tableUnlocked chan<- error, dropCutOverSentryTableOnce *sync.Once) error {
 	tx, err := this.db.Begin()
 	if err != nil {
 		tableLocked <- err
@ -945,7 +799,6 @@ func (this *Applier) AtomicCutOverMagicLock(sessionIdChan chan int64, tableLocke
 		tableLocked <- fmt.Errorf("Unexpected error in AtomicCutOverMagicLock(), injected to release blocking channel reads")
 		tableUnlocked <- fmt.Errorf("Unexpected error in AtomicCutOverMagicLock(), injected to release blocking channel reads")
 		tx.Rollback()
-		this.DropAtomicCutOverSentryTableIfExists()
 	}()

 	var sessionId int64
@ -1014,10 +867,12 @@ func (this *Applier) AtomicCutOverMagicLock(sessionIdChan chan int64, tableLocke
 		sql.EscapeName(this.migrationContext.GetOldTableName()),
 	)

-	if _, err := tx.Exec(query); err != nil {
-		this.migrationContext.Log.Errore(err)
-		// We DO NOT return here because we must `UNLOCK TABLES`!
-	}
+	dropCutOverSentryTableOnce.Do(func() {
+		if _, err := tx.Exec(query); err != nil {
+			this.migrationContext.Log.Errore(err)
+			// We DO NOT return here because we must `UNLOCK TABLES`!
+		}
+	})

 	// Tables still locked
 	this.migrationContext.Log.Infof("Releasing lock from %s.%s, %s.%s",
@ -1137,6 +992,7 @@ func (this *Applier) buildDMLEventQuery(dmlEvent *binlog.BinlogDMLEvent) (result

 // ApplyDMLEventQueries applies multiple DML queries onto the _ghost_ table
 func (this *Applier) ApplyDMLEventQueries(dmlEvents [](*binlog.BinlogDMLEvent)) error {
+
 	var totalDelta int64

 	err := func() error {
@ -1151,7 +1007,12 @@ func (this *Applier) ApplyDMLEventQueries(dmlEvents [](*binlog.BinlogDMLEvent))
 		}

 		sessionQuery := "SET SESSION time_zone = '+00:00'"
-		sessionQuery = fmt.Sprintf("%s, %s", sessionQuery, this.generateSqlModeQuery())
+
+		sqlModeAddendum := `,NO_AUTO_VALUE_ON_ZERO`
+		if !this.migrationContext.SkipStrictMode {
+			sqlModeAddendum = fmt.Sprintf("%s,STRICT_ALL_TABLES", sqlModeAddendum)
+		}
+		sessionQuery = fmt.Sprintf("%s, sql_mode = CONCAT(@@session.sql_mode, ',%s')", sessionQuery, sqlModeAddendum)

 		if _, err := tx.Exec(sessionQuery); err != nil {
 			return rollback(err)
@ -1161,20 +1022,11 @@ func (this *Applier) ApplyDMLEventQueries(dmlEvents [](*binlog.BinlogDMLEvent))
 				if buildResult.err != nil {
 					return rollback(buildResult.err)
 				}
-				result, err := tx.Exec(buildResult.query, buildResult.args...)
-				if err != nil {
-					err = fmt.Errorf("%w; query=%s; args=%+v", err, buildResult.query, buildResult.args)
+				if _, err := tx.Exec(buildResult.query, buildResult.args...); err != nil {
+					err = fmt.Errorf("%s; query=%s; args=%+v", err.Error(), buildResult.query, buildResult.args)
 					return rollback(err)
 				}
-
-				rowsAffected, err := result.RowsAffected()
-				if err != nil {
-					log.Warningf("error getting rows affected from DML event query: %s. i'm going to assume that the DML affected a single row, but this may result in inaccurate statistics", err)
-					rowsAffected = 1
-				}
-				// each DML is either a single insert (delta +1), update (delta +0) or delete (delta -1).
-				// multiplying by the rows actually affected (either 0 or 1) will give an accurate row delta for this DML event
-				totalDelta += buildResult.rowsDelta * rowsAffected
+				totalDelta += buildResult.rowsDelta
 			}
 		}
 		if err := tx.Commit(); err != nil {
--- a/go/logic/applier_test.go
+++ b/go/logic/applier_test.go
@ -1,185 +0,0 @@
-/*
-   Copyright 2022 GitHub Inc.
-         See https://github.com/github/gh-ost/blob/master/LICENSE
-*/
-
-package logic
-
-import (
-	"strings"
-	"testing"
-
-	test "github.com/openark/golib/tests"
-
-	"github.com/github/gh-ost/go/base"
-	"github.com/github/gh-ost/go/binlog"
-	"github.com/github/gh-ost/go/sql"
-)
-
-func TestApplierGenerateSqlModeQuery(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	applier := NewApplier(migrationContext)
-
-	{
-		test.S(t).ExpectEquals(
-			applier.generateSqlModeQuery(),
-			`sql_mode = CONCAT(@@session.sql_mode, ',NO_AUTO_VALUE_ON_ZERO,STRICT_ALL_TABLES')`,
-		)
-	}
-	{
-		migrationContext.SkipStrictMode = true
-		migrationContext.AllowZeroInDate = false
-		test.S(t).ExpectEquals(
-			applier.generateSqlModeQuery(),
-			`sql_mode = CONCAT(@@session.sql_mode, ',NO_AUTO_VALUE_ON_ZERO')`,
-		)
-	}
-	{
-		migrationContext.SkipStrictMode = false
-		migrationContext.AllowZeroInDate = true
-		test.S(t).ExpectEquals(
-			applier.generateSqlModeQuery(),
-			`sql_mode = REPLACE(REPLACE(CONCAT(@@session.sql_mode, ',NO_AUTO_VALUE_ON_ZERO,STRICT_ALL_TABLES'), 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', '')`,
-		)
-	}
-	{
-		migrationContext.SkipStrictMode = true
-		migrationContext.AllowZeroInDate = true
-		test.S(t).ExpectEquals(
-			applier.generateSqlModeQuery(),
-			`sql_mode = REPLACE(REPLACE(CONCAT(@@session.sql_mode, ',NO_AUTO_VALUE_ON_ZERO'), 'NO_ZERO_IN_DATE', ''), 'NO_ZERO_DATE', '')`,
-		)
-	}
-}
-
-func TestApplierUpdateModifiesUniqueKeyColumns(t *testing.T) {
-	columns := sql.NewColumnList([]string{"id", "item_id"})
-	columnValues := sql.ToColumnValues([]interface{}{123456, 42})
-
-	migrationContext := base.NewMigrationContext()
-	migrationContext.OriginalTableColumns = columns
-	migrationContext.UniqueKey = &sql.UniqueKey{
-		Name:    t.Name(),
-		Columns: *columns,
-	}
-
-	applier := NewApplier(migrationContext)
-
-	t.Run("unmodified", func(t *testing.T) {
-		modifiedColumn, isModified := applier.updateModifiesUniqueKeyColumns(&binlog.BinlogDMLEvent{
-			DatabaseName:      "test",
-			DML:               binlog.UpdateDML,
-			NewColumnValues:   columnValues,
-			WhereColumnValues: columnValues,
-		})
-		test.S(t).ExpectEquals(modifiedColumn, "")
-		test.S(t).ExpectFalse(isModified)
-	})
-
-	t.Run("modified", func(t *testing.T) {
-		modifiedColumn, isModified := applier.updateModifiesUniqueKeyColumns(&binlog.BinlogDMLEvent{
-			DatabaseName:      "test",
-			DML:               binlog.UpdateDML,
-			NewColumnValues:   sql.ToColumnValues([]interface{}{123456, 24}),
-			WhereColumnValues: columnValues,
-		})
-		test.S(t).ExpectEquals(modifiedColumn, "item_id")
-		test.S(t).ExpectTrue(isModified)
-	})
-}
-
-func TestApplierBuildDMLEventQuery(t *testing.T) {
-	columns := sql.NewColumnList([]string{"id", "item_id"})
-	columnValues := sql.ToColumnValues([]interface{}{123456, 42})
-
-	migrationContext := base.NewMigrationContext()
-	migrationContext.OriginalTableName = "test"
-	migrationContext.OriginalTableColumns = columns
-	migrationContext.SharedColumns = columns
-	migrationContext.MappedSharedColumns = columns
-	migrationContext.UniqueKey = &sql.UniqueKey{
-		Name:    t.Name(),
-		Columns: *columns,
-	}
-
-	applier := NewApplier(migrationContext)
-
-	t.Run("delete", func(t *testing.T) {
-		binlogEvent := &binlog.BinlogDMLEvent{
-			DatabaseName:      "test",
-			DML:               binlog.DeleteDML,
-			WhereColumnValues: columnValues,
-		}
-
-		res := applier.buildDMLEventQuery(binlogEvent)
-		test.S(t).ExpectEquals(len(res), 1)
-		test.S(t).ExpectNil(res[0].err)
-		test.S(t).ExpectEquals(strings.TrimSpace(res[0].query),
-			`delete /* gh-ost `+"`test`.`_test_gho`"+` */
-				from
-					`+"`test`.`_test_gho`"+`
-				where
-					((`+"`id`"+` = ?) and (`+"`item_id`"+` = ?))`)
-
-		test.S(t).ExpectEquals(len(res[0].args), 2)
-		test.S(t).ExpectEquals(res[0].args[0], 123456)
-		test.S(t).ExpectEquals(res[0].args[1], 42)
-	})
-
-	t.Run("insert", func(t *testing.T) {
-		binlogEvent := &binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}
-		res := applier.buildDMLEventQuery(binlogEvent)
-		test.S(t).ExpectEquals(len(res), 1)
-		test.S(t).ExpectNil(res[0].err)
-		test.S(t).ExpectEquals(strings.TrimSpace(res[0].query),
-			`replace /* gh-ost `+"`test`.`_test_gho`"+` */ into
-				`+"`test`.`_test_gho`"+`
-					`+"(`id`, `item_id`)"+`
-				values
-					(?, ?)`)
-		test.S(t).ExpectEquals(len(res[0].args), 2)
-		test.S(t).ExpectEquals(res[0].args[0], 123456)
-		test.S(t).ExpectEquals(res[0].args[1], 42)
-	})
-
-	t.Run("update", func(t *testing.T) {
-		binlogEvent := &binlog.BinlogDMLEvent{
-			DatabaseName:      "test",
-			DML:               binlog.UpdateDML,
-			NewColumnValues:   columnValues,
-			WhereColumnValues: columnValues,
-		}
-		res := applier.buildDMLEventQuery(binlogEvent)
-		test.S(t).ExpectEquals(len(res), 1)
-		test.S(t).ExpectNil(res[0].err)
-		test.S(t).ExpectEquals(strings.TrimSpace(res[0].query),
-			`update /* gh-ost `+"`test`.`_test_gho`"+` */
-					`+"`test`.`_test_gho`"+`
-				set
-					`+"`id`"+`=?, `+"`item_id`"+`=?
-				where
-					((`+"`id`"+` = ?) and (`+"`item_id`"+` = ?))`)
-		test.S(t).ExpectEquals(len(res[0].args), 4)
-		test.S(t).ExpectEquals(res[0].args[0], 123456)
-		test.S(t).ExpectEquals(res[0].args[1], 42)
-		test.S(t).ExpectEquals(res[0].args[2], 123456)
-		test.S(t).ExpectEquals(res[0].args[3], 42)
-	})
-}
-
-func TestApplierInstantDDL(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrationContext.DatabaseName = "test"
-	migrationContext.OriginalTableName = "mytable"
-	migrationContext.AlterStatementOptions = "ADD INDEX (foo)"
-	applier := NewApplier(migrationContext)
-
-	t.Run("instantDDLstmt", func(t *testing.T) {
-		stmt := applier.generateInstantDDLQuery()
-		test.S(t).ExpectEquals(stmt, "ALTER /* gh-ost */ TABLE `test`.`mytable` ADD INDEX (foo), ALGORITHM=INSTANT")
-	})
-}
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@ -1,5 +1,6 @@
 /*
-   Copyright 2022 GitHub Inc.
+/*
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -7,14 +8,13 @@ package logic

 import (
 	"fmt"
-	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"sync/atomic"

 	"github.com/github/gh-ost/go/base"
-	"github.com/openark/golib/log"
+	"github.com/outbrain/golib/log"
 )

 const (
@ -35,16 +35,18 @@ const (

 type HooksExecutor struct {
 	migrationContext *base.MigrationContext
-	writer           io.Writer
 }

 func NewHooksExecutor(migrationContext *base.MigrationContext) *HooksExecutor {
 	return &HooksExecutor{
 		migrationContext: migrationContext,
-		writer:           os.Stderr,
 	}
 }

+func (this *HooksExecutor) initHooks() error {
+	return nil
+}
+
 func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) []string {
 	env := os.Environ()
 	env = append(env, fmt.Sprintf("GH_OST_DATABASE_NAME=%s", this.migrationContext.DatabaseName))
@ -62,26 +64,26 @@ func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) [
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_HOST=%s", this.migrationContext.GetInspectorHostname()))
 	env = append(env, fmt.Sprintf("GH_OST_EXECUTING_HOST=%s", this.migrationContext.Hostname))
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_LAG=%f", this.migrationContext.GetCurrentLagDuration().Seconds()))
-	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_PROGRESS=%f", this.migrationContext.GetProgressPct()))
-	env = append(env, fmt.Sprintf("GH_OST_ETA_SECONDS=%d", this.migrationContext.GetETASeconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT=%s", this.migrationContext.HooksHintMessage))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_OWNER=%s", this.migrationContext.HooksHintOwner))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_TOKEN=%s", this.migrationContext.HooksHintToken))
 	env = append(env, fmt.Sprintf("GH_OST_DRY_RUN=%t", this.migrationContext.Noop))

-	env = append(env, extraVariables...)
+	for _, variable := range extraVariables {
+		env = append(env, variable)
+	}
 	return env
 }

 // executeHook executes a command, and sets relevant environment variables
-// combined output & error are printed to the configured writer.
+// combined output & error are printed to gh-ost's standard error.
 func (this *HooksExecutor) executeHook(hook string, extraVariables ...string) error {
 	cmd := exec.Command(hook)
 	cmd.Env = this.applyEnvironmentVariables(extraVariables...)

 	combinedOutput, err := cmd.CombinedOutput()
-	fmt.Fprintln(this.writer, string(combinedOutput))
+	fmt.Fprintln(os.Stderr, string(combinedOutput))
 	return log.Errore(err)
 }

--- a/go/logic/hooks_test.go
+++ b/go/logic/hooks_test.go
@ -1,113 +0,0 @@
-/*
-   Copyright 2022 GitHub Inc.
-         See https://github.com/github/gh-ost/blob/master/LICENSE
-*/
-
-package logic
-
-import (
-	"bufio"
-	"bytes"
-	"fmt"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"testing"
-	"time"
-
-	"github.com/openark/golib/tests"
-
-	"github.com/github/gh-ost/go/base"
-)
-
-func TestHooksExecutorExecuteHooks(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrationContext.AlterStatement = "ENGINE=InnoDB"
-	migrationContext.DatabaseName = "test"
-	migrationContext.Hostname = "test.example.com"
-	migrationContext.OriginalTableName = "tablename"
-	migrationContext.RowsDeltaEstimate = 1
-	migrationContext.RowsEstimate = 122
-	migrationContext.TotalRowsCopied = 123456
-	migrationContext.SetETADuration(time.Minute)
-	migrationContext.SetProgressPct(50)
-	hooksExecutor := NewHooksExecutor(migrationContext)
-
-	writeTmpHookFunc := func(testName, hookName, script string) (path string, err error) {
-		if path, err = os.MkdirTemp("", testName); err != nil {
-			return path, err
-		}
-		err = os.WriteFile(filepath.Join(path, hookName), []byte(script), 0777)
-		return path, err
-	}
-
-	t.Run("does-not-exist", func(t *testing.T) {
-		migrationContext.HooksPath = "/does/not/exist"
-		tests.S(t).ExpectNil(hooksExecutor.executeHooks("test-hook"))
-	})
-
-	t.Run("failed", func(t *testing.T) {
-		var err error
-		if migrationContext.HooksPath, err = writeTmpHookFunc(
-			"TestHooksExecutorExecuteHooks-failed",
-			"failed-hook",
-			"#!/bin/sh\nexit 1",
-		); err != nil {
-			panic(err)
-		}
-		defer os.RemoveAll(migrationContext.HooksPath)
-		tests.S(t).ExpectNotNil(hooksExecutor.executeHooks("failed-hook"))
-	})
-
-	t.Run("success", func(t *testing.T) {
-		var err error
-		if migrationContext.HooksPath, err = writeTmpHookFunc(
-			"TestHooksExecutorExecuteHooks-success",
-			"success-hook",
-			"#!/bin/sh\nenv",
-		); err != nil {
-			panic(err)
-		}
-		defer os.RemoveAll(migrationContext.HooksPath)
-
-		var buf bytes.Buffer
-		hooksExecutor.writer = &buf
-		tests.S(t).ExpectNil(hooksExecutor.executeHooks("success-hook", "TEST="+t.Name()))
-
-		scanner := bufio.NewScanner(&buf)
-		for scanner.Scan() {
-			split := strings.SplitN(scanner.Text(), "=", 2)
-			switch split[0] {
-			case "GH_OST_COPIED_ROWS":
-				copiedRows, _ := strconv.ParseInt(split[1], 10, 64)
-				tests.S(t).ExpectEquals(copiedRows, migrationContext.TotalRowsCopied)
-			case "GH_OST_DATABASE_NAME":
-				tests.S(t).ExpectEquals(split[1], migrationContext.DatabaseName)
-			case "GH_OST_DDL":
-				tests.S(t).ExpectEquals(split[1], migrationContext.AlterStatement)
-			case "GH_OST_DRY_RUN":
-				tests.S(t).ExpectEquals(split[1], "false")
-			case "GH_OST_ESTIMATED_ROWS":
-				estimatedRows, _ := strconv.ParseInt(split[1], 10, 64)
-				tests.S(t).ExpectEquals(estimatedRows, int64(123))
-			case "GH_OST_ETA_SECONDS":
-				etaSeconds, _ := strconv.ParseInt(split[1], 10, 64)
-				tests.S(t).ExpectEquals(etaSeconds, int64(60))
-			case "GH_OST_EXECUTING_HOST":
-				tests.S(t).ExpectEquals(split[1], migrationContext.Hostname)
-			case "GH_OST_GHOST_TABLE_NAME":
-				tests.S(t).ExpectEquals(split[1], fmt.Sprintf("_%s_gho", migrationContext.OriginalTableName))
-			case "GH_OST_OLD_TABLE_NAME":
-				tests.S(t).ExpectEquals(split[1], fmt.Sprintf("_%s_del", migrationContext.OriginalTableName))
-			case "GH_OST_PROGRESS":
-				progress, _ := strconv.ParseFloat(split[1], 64)
-				tests.S(t).ExpectEquals(progress, 50.0)
-			case "GH_OST_TABLE_NAME":
-				tests.S(t).ExpectEquals(split[1], migrationContext.OriginalTableName)
-			case "TEST":
-				tests.S(t).ExpectEquals(split[1], t.Name())
-			}
-		}
-	})
-}
--- a/go/logic/inspect.go
+++ b/go/logic/inspect.go
@ -1,14 +1,12 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

 package logic

 import (
-	"context"
 	gosql "database/sql"
-	"errors"
 	"fmt"
 	"reflect"
 	"strings"
@ -19,7 +17,7 @@ import (
 	"github.com/github/gh-ost/go/mysql"
 	"github.com/github/gh-ost/go/sql"

-	"github.com/openark/golib/sqlutils"
+	"github.com/outbrain/golib/sqlutils"
 )

 const startSlavePostWaitMilliseconds = 500 * time.Millisecond
@ -31,14 +29,12 @@ type Inspector struct {
 	db                  *gosql.DB
 	informationSchemaDb *gosql.DB
 	migrationContext    *base.MigrationContext
-	name                string
 }

 func NewInspector(migrationContext *base.MigrationContext) *Inspector {
 	return &Inspector{
 		connectionConfig: migrationContext.InspectorConnectionConfig,
 		migrationContext: migrationContext,
-		name:             "inspector",
 	}
 }

@ -56,7 +52,7 @@ func (this *Inspector) InitDBConnections() (err error) {
 	if err := this.validateConnection(); err != nil {
 		return err
 	}
-	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform && !this.migrationContext.AzureMySQL {
+	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform {
 		if impliedKey, err := mysql.GetInstanceKey(this.db); err != nil {
 			return err
 		} else {
@ -113,10 +109,6 @@ func (this *Inspector) InspectOriginalTable() (err error) {
 	if err != nil {
 		return err
 	}
-	this.migrationContext.OriginalTableAutoIncrement, err = this.getAutoIncrementValue(this.migrationContext.OriginalTableName)
-	if err != nil {
-		return err
-	}
 	return nil
 }

@ -133,7 +125,10 @@ func (this *Inspector) inspectOriginalAndGhostTables() (err error) {
 	if err != nil {
 		return err
 	}
-	sharedUniqueKeys := this.getSharedUniqueKeys(this.migrationContext.OriginalTableUniqueKeys, this.migrationContext.GhostTableUniqueKeys)
+	sharedUniqueKeys, err := this.getSharedUniqueKeys(this.migrationContext.OriginalTableUniqueKeys, this.migrationContext.GhostTableUniqueKeys)
+	if err != nil {
+		return err
+	}
 	for i, sharedUniqueKey := range sharedUniqueKeys {
 		this.applyColumnTypes(this.migrationContext.DatabaseName, this.migrationContext.OriginalTableName, &sharedUniqueKey.Columns)
 		uniqueKeyIsValid := true
@ -186,20 +181,9 @@ func (this *Inspector) inspectOriginalAndGhostTables() (err error) {
 		if column.Name == mappedColumn.Name && column.Type == sql.DateTimeColumnType && mappedColumn.Type == sql.TimestampColumnType {
 			this.migrationContext.MappedSharedColumns.SetConvertDatetimeToTimestamp(column.Name, this.migrationContext.ApplierTimeZone)
 		}
-		if column.Name == mappedColumn.Name && column.Type == sql.EnumColumnType && mappedColumn.Charset != "" {
-			this.migrationContext.MappedSharedColumns.SetEnumToTextConversion(column.Name)
-			this.migrationContext.MappedSharedColumns.SetEnumValues(column.Name, column.EnumValues)
-		}
-		if column.Name == mappedColumn.Name && column.Charset != mappedColumn.Charset {
-			this.migrationContext.SharedColumns.SetCharsetConversion(column.Name, column.Charset, mappedColumn.Charset)
-		}
 	}

 	for _, column := range this.migrationContext.UniqueKey.Columns.Columns() {
-		if this.migrationContext.GhostTableVirtualColumns.GetColumn(column.Name) != nil {
-			// this is a virtual column
-			continue
-		}
 		if this.migrationContext.MappedSharedColumns.HasTimezoneConversion(column.Name) {
 			return fmt.Errorf("No support at this time for converting a column from DATETIME to TIMESTAMP that is also part of the chosen unique key. Column: %s, key: %s", column.Name, this.migrationContext.UniqueKey.Name)
 		}
@ -214,7 +198,7 @@ func (this *Inspector) validateConnection() error {
 		return fmt.Errorf("MySQL replication length limited to 32 characters. See https://dev.mysql.com/doc/refman/5.7/en/assigning-passwords.html")
 	}

-	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name)
+	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext)
 	this.migrationContext.InspectorMySQLVersion = version
 	return err
 }
@ -285,7 +269,7 @@ func (this *Inspector) validateGrants() error {
 // It is entirely possible, for example, that the replication is using 'STATEMENT'
 // binlog format even as the variable says 'ROW'
 func (this *Inspector) restartReplication() error {
-	this.migrationContext.Log.Infof("Restarting replication on %s to make sure binlog settings apply to replication thread", this.connectionConfig.Key.String())
+	this.migrationContext.Log.Infof("Restarting replication on %s:%d to make sure binlog settings apply to replication thread", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)

 	masterKey, _ := mysql.GetMasterKeyFromSlaveStatus(this.connectionConfig)
 	if masterKey == nil {
@ -344,13 +328,13 @@ func (this *Inspector) validateBinlogs() error {
 		return err
 	}
 	if !hasBinaryLogs {
-		return fmt.Errorf("%s must have binary logs enabled", this.connectionConfig.Key.String())
+		return fmt.Errorf("%s:%d must have binary logs enabled", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 	}
 	if this.migrationContext.RequiresBinlogFormatChange() {
 		if !this.migrationContext.SwitchToRowBinlogFormat {
-			return fmt.Errorf("You must be using ROW binlog format. I can switch it for you, provided --switch-to-rbr and that %s doesn't have replicas", this.connectionConfig.Key.String())
+			return fmt.Errorf("You must be using ROW binlog format. I can switch it for you, provided --switch-to-rbr and that %s:%d doesn't have replicas", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 		}
-		query := `show /* gh-ost */ slave hosts`
+		query := fmt.Sprintf(`show /* gh-ost */ slave hosts`)
 		countReplicas := 0
 		err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error {
 			countReplicas++
@ -360,20 +344,21 @@ func (this *Inspector) validateBinlogs() error {
 			return err
 		}
 		if countReplicas > 0 {
-			return fmt.Errorf("%s has %s binlog_format, but I'm too scared to change it to ROW because it has replicas. Bailing out", this.connectionConfig.Key.String(), this.migrationContext.OriginalBinlogFormat)
+			return fmt.Errorf("%s:%d has %s binlog_format, but I'm too scared to change it to ROW because it has replicas. Bailing out", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogFormat)
 		}
-		this.migrationContext.Log.Infof("%s has %s binlog_format. I will change it to ROW, and will NOT change it back, even in the event of failure.", this.connectionConfig.Key.String(), this.migrationContext.OriginalBinlogFormat)
+		this.migrationContext.Log.Infof("%s:%d has %s binlog_format. I will change it to ROW, and will NOT change it back, even in the event of failure.", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogFormat)
 	}
 	query = `select @@global.binlog_row_image`
 	if err := this.db.QueryRow(query).Scan(&this.migrationContext.OriginalBinlogRowImage); err != nil {
-		return err
+		// Only as of 5.6. We wish to support 5.5 as well
+		this.migrationContext.OriginalBinlogRowImage = "FULL"
 	}
 	this.migrationContext.OriginalBinlogRowImage = strings.ToUpper(this.migrationContext.OriginalBinlogRowImage)
 	if this.migrationContext.OriginalBinlogRowImage != "FULL" {
-		return fmt.Errorf("%s has '%s' binlog_row_image, and only 'FULL' is supported. This operation cannot proceed. You may `set global binlog_row_image='full'` and try again", this.connectionConfig.Key.String(), this.migrationContext.OriginalBinlogRowImage)
+		return fmt.Errorf("%s:%d has '%s' binlog_row_image, and only 'FULL' is supported. This operation cannot proceed. You may `set global binlog_row_image='full'` and try again", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port, this.migrationContext.OriginalBinlogRowImage)
 	}

-	this.migrationContext.Log.Infof("binary logs validated on %s", this.connectionConfig.Key.String())
+	this.migrationContext.Log.Infof("binary logs validated on %s:%d", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 	return nil
 }

@ -386,25 +371,25 @@ func (this *Inspector) validateLogSlaveUpdates() error {
 	}

 	if logSlaveUpdates {
-		this.migrationContext.Log.Infof("log_slave_updates validated on %s", this.connectionConfig.Key.String())
+		this.migrationContext.Log.Infof("log_slave_updates validated on %s:%d", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 		return nil
 	}

 	if this.migrationContext.IsTungsten {
-		this.migrationContext.Log.Warningf("log_slave_updates not found on %s, but --tungsten provided, so I'm proceeding", this.connectionConfig.Key.String())
+		this.migrationContext.Log.Warningf("log_slave_updates not found on %s:%d, but --tungsten provided, so I'm proceeding", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 		return nil
 	}

 	if this.migrationContext.TestOnReplica || this.migrationContext.MigrateOnReplica {
-		return fmt.Errorf("%s must have log_slave_updates enabled for testing/migrating on replica", this.connectionConfig.Key.String())
+		return fmt.Errorf("%s:%d must have log_slave_updates enabled for testing/migrating on replica", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 	}

 	if this.migrationContext.InspectorIsAlsoApplier() {
-		this.migrationContext.Log.Warningf("log_slave_updates not found on %s, but executing directly on master, so I'm proceeding", this.connectionConfig.Key.String())
+		this.migrationContext.Log.Warningf("log_slave_updates not found on %s:%d, but executing directly on master, so I'm proceeding", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 		return nil
 	}

-	return fmt.Errorf("%s must have log_slave_updates enabled for executing migration", this.connectionConfig.Key.String())
+	return fmt.Errorf("%s:%d must have log_slave_updates enabled for executing migration", this.connectionConfig.Key.Hostname, this.connectionConfig.Key.Port)
 }

 // validateTable makes sure the table we need to operate on actually exists
@ -535,37 +520,17 @@ func (this *Inspector) estimateTableRowsViaExplain() error {
 }

 // CountTableRows counts exact number of rows on the original table
-func (this *Inspector) CountTableRows(ctx context.Context) error {
+func (this *Inspector) CountTableRows() error {
 	atomic.StoreInt64(&this.migrationContext.CountingRowsFlag, 1)
 	defer atomic.StoreInt64(&this.migrationContext.CountingRowsFlag, 0)

 	this.migrationContext.Log.Infof("As instructed, I'm issuing a SELECT COUNT(*) on the table. This may take a while")

-	conn, err := this.db.Conn(ctx)
-	if err != nil {
-		return err
-	}
-	defer conn.Close()
-
-	var connectionID string
-	if err := conn.QueryRowContext(ctx, `SELECT /* gh-ost */ CONNECTION_ID()`).Scan(&connectionID); err != nil {
-		return err
-	}
-
-	query := fmt.Sprintf(`select /* gh-ost */ count(*) as count_rows from %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
+	query := fmt.Sprintf(`select /* gh-ost */ count(*) as rows from %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
 	var rowsEstimate int64
-	if err := conn.QueryRowContext(ctx, query).Scan(&rowsEstimate); err != nil {
-		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
-			this.migrationContext.Log.Infof("exact row count cancelled (%s), likely because I'm about to cut over. I'm going to kill that query.", ctx.Err())
-			return mysql.Kill(this.db, connectionID)
-		}
+	if err := this.db.QueryRow(query).Scan(&rowsEstimate); err != nil {
 		return err
 	}
-
-	// row count query finished. nil out the cancel func, so the main migration thread
-	// doesn't bother calling it after row copy is done.
-	this.migrationContext.SetCountTableRowsCancelFunc(nil)
-
 	atomic.StoreInt64(&this.migrationContext.RowsEstimate, rowsEstimate)
 	this.migrationContext.UsedRowsEstimateMethod = base.CountRowsEstimate

@ -588,7 +553,6 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 	err := sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error {
 		columnName := m.GetString("COLUMN_NAME")
 		columnType := m.GetString("COLUMN_TYPE")
-		columnOctetLength := m.GetUint("CHARACTER_OCTET_LENGTH")
 		for _, columnsList := range columnsLists {
 			column := columnsList.GetColumn(columnName)
 			if column == nil {
@ -615,11 +579,6 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 			}
 			if strings.HasPrefix(columnType, "enum") {
 				column.Type = sql.EnumColumnType
-				column.EnumValues = sql.ParseEnumValues(m.GetString("COLUMN_TYPE"))
-			}
-			if strings.HasPrefix(columnType, "binary") {
-				column.Type = sql.BinaryColumnType
-				column.BinaryOctetLength = columnOctetLength
 			}
 			if charset := m.GetString("CHARACTER_SET_NAME"); charset != "" {
 				column.Charset = charset
@ -630,24 +589,6 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 	return err
 }

-// getAutoIncrementValue get's the original table's AUTO_INCREMENT value, if exists (0 value if not exists)
-func (this *Inspector) getAutoIncrementValue(tableName string) (autoIncrement uint64, err error) {
-	query := `
-		SELECT
-			AUTO_INCREMENT
-		FROM INFORMATION_SCHEMA.TABLES
-		WHERE
-			TABLES.TABLE_SCHEMA = ?
-			AND TABLES.TABLE_NAME = ?
-			AND AUTO_INCREMENT IS NOT NULL
-  `
-	err = sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error {
-		autoIncrement = m.GetUint64("AUTO_INCREMENT")
-		return nil
-	}, this.migrationContext.DatabaseName, tableName)
-	return autoIncrement, err
-}
-
 // getCandidateUniqueKeys investigates a table and returns the list of unique keys
 // candidate for chunking
 func (this *Inspector) getCandidateUniqueKeys(tableName string) (uniqueKeys [](*sql.UniqueKey), err error) {
@ -727,7 +668,7 @@ func (this *Inspector) getCandidateUniqueKeys(tableName string) (uniqueKeys [](*

 // getSharedUniqueKeys returns the intersection of two given unique keys,
 // testing by list of columns
-func (this *Inspector) getSharedUniqueKeys(originalUniqueKeys, ghostUniqueKeys []*sql.UniqueKey) (uniqueKeys []*sql.UniqueKey) {
+func (this *Inspector) getSharedUniqueKeys(originalUniqueKeys, ghostUniqueKeys [](*sql.UniqueKey)) (uniqueKeys [](*sql.UniqueKey), err error) {
 	// We actually do NOT rely on key name, just on the set of columns. This is because maybe
 	// the ALTER is on the name itself...
 	for _, originalUniqueKey := range originalUniqueKeys {
@ -737,7 +678,7 @@ func (this *Inspector) getSharedUniqueKeys(originalUniqueKeys, ghostUniqueKeys [
 			}
 		}
 	}
-	return uniqueKeys
+	return uniqueKeys, nil
 }

 // getSharedColumns returns the intersection of two lists of columns in same order as the first list
@ -826,4 +767,5 @@ func (this *Inspector) getReplicationLag() (replicationLag time.Duration, err er
 func (this *Inspector) Teardown() {
 	this.db.Close()
 	this.informationSchemaDb.Close()
+	return
 }
--- a/go/logic/inspect_test.go
+++ b/go/logic/inspect_test.go
@ -1,31 +0,0 @@
-/*
-   Copyright 2022 GitHub Inc.
-         See https://github.com/github/gh-ost/blob/master/LICENSE
-*/
-
-package logic
-
-import (
-	"testing"
-
-	test "github.com/openark/golib/tests"
-
-	"github.com/github/gh-ost/go/sql"
-)
-
-func TestInspectGetSharedUniqueKeys(t *testing.T) {
-	origUniqKeys := []*sql.UniqueKey{
-		{Columns: *sql.NewColumnList([]string{"id", "item_id"})},
-		{Columns: *sql.NewColumnList([]string{"id", "org_id"})},
-	}
-	ghostUniqKeys := []*sql.UniqueKey{
-		{Columns: *sql.NewColumnList([]string{"id", "item_id"})},
-		{Columns: *sql.NewColumnList([]string{"id", "org_id"})},
-		{Columns: *sql.NewColumnList([]string{"item_id", "user_id"})},
-	}
-	inspector := &Inspector{}
-	sharedUniqKeys := inspector.getSharedUniqueKeys(origUniqKeys, ghostUniqKeys)
-	test.S(t).ExpectEquals(len(sharedUniqKeys), 2)
-	test.S(t).ExpectEquals(sharedUniqKeys[0].Columns.String(), "id,item_id")
-	test.S(t).ExpectEquals(sharedUniqKeys[1].Columns.String(), "id,org_id")
-}
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@ -1,18 +1,17 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

 package logic

 import (
-	"context"
-	"errors"
 	"fmt"
 	"io"
 	"math"
 	"os"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"

@ -22,17 +21,11 @@ import (
 	"github.com/github/gh-ost/go/sql"
 )

-var (
-	ErrMigratorUnsupportedRenameAlter = errors.New("ALTER statement seems to RENAME the table. This is not supported, and you should run your RENAME outside gh-ost.")
-)
-
 type ChangelogState string

 const (
-	AllEventsUpToLockProcessed ChangelogState = "AllEventsUpToLockProcessed"
 	GhostTableMigrated         ChangelogState = "GhostTableMigrated"
-	Migrated                   ChangelogState = "Migrated"
-	ReadMigrationRangeValues   ChangelogState = "ReadMigrationRangeValues"
+	AllEventsUpToLockProcessed                = "AllEventsUpToLockProcessed"
 )

 func ReadChangelogState(s string) ChangelogState {
@ -68,7 +61,6 @@ const (

 // Migrator is the main schema migration flow manager.
 type Migrator struct {
-	appVersion       string
 	parser           *sql.AlterTableParser
 	inspector        *Inspector
 	applier          *Applier
@ -94,10 +86,8 @@ type Migrator struct {
 	finishedMigrating int64
 }

-func NewMigrator(context *base.MigrationContext, appVersion string) *Migrator {
+func NewMigrator(context *base.MigrationContext) *Migrator {
 	migrator := &Migrator{
-		appVersion:                 appVersion,
-		hooksExecutor:              NewHooksExecutor(context),
 		migrationContext:           context,
 		parser:                     sql.NewAlterTableParser(),
 		ghostTableMigrated:         make(chan bool),
@ -113,6 +103,15 @@ func NewMigrator(context *base.MigrationContext, appVersion string) *Migrator {
 	return migrator
 }

+// initiateHooksExecutor
+func (this *Migrator) initiateHooksExecutor() (err error) {
+	this.hooksExecutor = NewHooksExecutor(this.migrationContext)
+	if err := this.hooksExecutor.initHooks(); err != nil {
+		return err
+	}
+	return nil
+}
+
 // sleepWhileTrue sleeps indefinitely until the given function returns 'false'
 // (or fails with error)
 func (this *Migrator) sleepWhileTrue(operation func() (bool, error)) error {
@ -177,6 +176,16 @@ func (this *Migrator) retryOperationWithExponentialBackoff(operation func() erro
 	return err
 }

+// executeAndThrottleOnError executes a given function. If it errors, it
+// throttles.
+func (this *Migrator) executeAndThrottleOnError(operation func() error) (err error) {
+	if err := operation(); err != nil {
+		this.throttler.throttle(nil)
+		return err
+	}
+	return nil
+}
+
 // consumeRowCopyComplete blocks on the rowCopyComplete channel once, and then
 // consumes and drops any further incoming events that may be left hanging.
 func (this *Migrator) consumeRowCopyComplete() {
@ -198,73 +207,57 @@ func (this *Migrator) canStopStreaming() bool {
 	return atomic.LoadInt64(&this.migrationContext.CutOverCompleteFlag) != 0
 }

-// onChangelogEvent is called when a binlog event operation on the changelog table is intercepted.
-func (this *Migrator) onChangelogEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
+// onChangelogStateEvent is called when a binlog event operation on the changelog table is intercepted.
+func (this *Migrator) onChangelogStateEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
 	// Hey, I created the changelog table, I know the type of columns it has!
-	switch hint := dmlEvent.NewColumnValues.StringColumn(2); hint {
-	case "state":
-		return this.onChangelogStateEvent(dmlEvent)
-	case "heartbeat":
-		return this.onChangelogHeartbeatEvent(dmlEvent)
-	default:
+	if hint := dmlEvent.NewColumnValues.StringColumn(2); hint != "state" {
 		return nil
 	}
-}
-
-func (this *Migrator) onChangelogStateEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
 	changelogStateString := dmlEvent.NewColumnValues.StringColumn(3)
 	changelogState := ReadChangelogState(changelogStateString)
 	this.migrationContext.Log.Infof("Intercepted changelog state %s", changelogState)
 	switch changelogState {
-	case Migrated, ReadMigrationRangeValues:
-		// no-op event
 	case GhostTableMigrated:
-		this.ghostTableMigrated <- true
-	case AllEventsUpToLockProcessed:
-		var applyEventFunc tableWriteFunc = func() error {
-			this.allEventsUpToLockProcessed <- changelogStateString
-			return nil
+		{
+			this.ghostTableMigrated <- true
+		}
+	case AllEventsUpToLockProcessed:
+		{
+			var applyEventFunc tableWriteFunc = func() error {
+				this.allEventsUpToLockProcessed <- changelogStateString
+				return nil
+			}
+			// at this point we know all events up to lock have been read from the streamer,
+			// because the streamer works sequentially. So those events are either already handled,
+			// or have event functions in applyEventsQueue.
+			// So as not to create a potential deadlock, we write this func to applyEventsQueue
+			// asynchronously, understanding it doesn't really matter.
+			go func() {
+				this.applyEventsQueue <- newApplyEventStructByFunc(&applyEventFunc)
+			}()
 		}
-		// at this point we know all events up to lock have been read from the streamer,
-		// because the streamer works sequentially. So those events are either already handled,
-		// or have event functions in applyEventsQueue.
-		// So as not to create a potential deadlock, we write this func to applyEventsQueue
-		// asynchronously, understanding it doesn't really matter.
-		go func() {
-			this.applyEventsQueue <- newApplyEventStructByFunc(&applyEventFunc)
-		}()
 	default:
-		return fmt.Errorf("Unknown changelog state: %+v", changelogState)
+		{
+			return fmt.Errorf("Unknown changelog state: %+v", changelogState)
+		}
 	}
 	this.migrationContext.Log.Infof("Handled changelog state %s", changelogState)
 	return nil
 }

-func (this *Migrator) onChangelogHeartbeatEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
-	changelogHeartbeatString := dmlEvent.NewColumnValues.StringColumn(3)
-
-	heartbeatTime, err := time.Parse(time.RFC3339Nano, changelogHeartbeatString)
-	if err != nil {
-		return this.migrationContext.Log.Errore(err)
-	} else {
-		this.migrationContext.SetLastHeartbeatOnChangelogTime(heartbeatTime)
-		return nil
-	}
-}
-
 // listenOnPanicAbort aborts on abort request
 func (this *Migrator) listenOnPanicAbort() {
 	err := <-this.migrationContext.PanicAbort
 	this.migrationContext.Log.Fatale(err)
 }

-// validateAlterStatement validates the `alter` statement meets criteria.
+// validateStatement validates the `alter` statement meets criteria.
 // At this time this means:
 // - column renames are approved
 // - no table rename allowed
-func (this *Migrator) validateAlterStatement() (err error) {
+func (this *Migrator) validateStatement() (err error) {
 	if this.parser.IsRenameTable() {
-		return ErrMigratorUnsupportedRenameAlter
+		return fmt.Errorf("ALTER statement seems to RENAME the table. This is not supported, and you should run your RENAME outside gh-ost.")
 	}
 	if this.parser.HasNonTrivialRenames() && !this.migrationContext.SkipRenamedColumns {
 		this.migrationContext.ColumnRenameMap = this.parser.GetNonTrivialRenames()
@ -287,8 +280,8 @@ func (this *Migrator) countTableRows() (err error) {
 		return nil
 	}

-	countRowsFunc := func(ctx context.Context) error {
-		if err := this.inspector.CountTableRows(ctx); err != nil {
+	countRowsFunc := func() error {
+		if err := this.inspector.CountTableRows(); err != nil {
 			return err
 		}
 		if err := this.hooksExecutor.onRowCountComplete(); err != nil {
@ -298,17 +291,12 @@ func (this *Migrator) countTableRows() (err error) {
 	}

 	if this.migrationContext.ConcurrentCountTableRows {
-		// store a cancel func so we can stop this query before a cut over
-		rowCountContext, rowCountCancel := context.WithCancel(context.Background())
-		this.migrationContext.SetCountTableRowsCancelFunc(rowCountCancel)
-
 		this.migrationContext.Log.Infof("As instructed, counting rows in the background; meanwhile I will use an estimated count, and will update it later on")
-		go countRowsFunc(rowCountContext)
-
+		go countRowsFunc()
 		// and we ignore errors, because this turns to be a background job
 		return nil
 	}
-	return countRowsFunc(context.Background())
+	return countRowsFunc()
 }

 func (this *Migrator) createFlagFiles() (err error) {
@ -333,13 +321,16 @@ func (this *Migrator) Migrate() (err error) {

 	go this.listenOnPanicAbort()

+	if err := this.initiateHooksExecutor(); err != nil {
+		return err
+	}
 	if err := this.hooksExecutor.onStartup(); err != nil {
 		return err
 	}
 	if err := this.parser.ParseAlterStatement(this.migrationContext.AlterStatement); err != nil {
 		return err
 	}
-	if err := this.validateAlterStatement(); err != nil {
+	if err := this.validateStatement(); err != nil {
 		return err
 	}

@ -359,17 +350,6 @@ func (this *Migrator) Migrate() (err error) {
 	if err := this.createFlagFiles(); err != nil {
 		return err
 	}
-	// In MySQL 8.0 (and possibly earlier) some DDL statements can be applied instantly.
-	// Attempt to do this if AttemptInstantDDL is set.
-	if this.migrationContext.AttemptInstantDDL {
-		this.migrationContext.Log.Infof("Attempting to execute alter with ALGORITHM=INSTANT")
-		if err := this.applier.AttemptInstantDDL(); err == nil {
-			this.migrationContext.Log.Infof("Success! table %s.%s migrated instantly", sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
-			return nil
-		} else {
-			this.migrationContext.Log.Infof("ALGORITHM=INSTANT not supported for this operation, proceeding with original algorithm: %s", err)
-		}
-	}

 	initialLag, _ := this.inspector.getReplicationLag()
 	this.migrationContext.Log.Infof("Waiting for ghost table to be migrated. Current lag is %+v", initialLag)
@ -401,9 +381,9 @@ func (this *Migrator) Migrate() (err error) {
 	if err := this.applier.ReadMigrationRangeValues(); err != nil {
 		return err
 	}
-
-	this.initiateThrottler()
-
+	if err := this.initiateThrottler(); err != nil {
+		return err
+	}
 	if err := this.hooksExecutor.onBeforeRowCopy(); err != nil {
 		return err
 	}
@ -420,10 +400,6 @@ func (this *Migrator) Migrate() (err error) {
 	}
 	this.printStatus(ForcePrintStatusRule)

-	if this.migrationContext.IsCountingTableRows() {
-		this.migrationContext.Log.Info("stopping query for exact row count, because that can accidentally lock out the cut over")
-		this.migrationContext.CancelTableRowsCount()
-	}
 	if err := this.hooksExecutor.onBeforeCutOver(); err != nil {
 		return err
 	}
@ -500,13 +476,6 @@ func (this *Migrator) cutOver() (err error) {
 	this.migrationContext.Log.Debugf("checking for cut-over postpone")
 	this.sleepWhileTrue(
 		func() (bool, error) {
-			heartbeatLag := this.migrationContext.TimeSinceLastHeartbeatOnChangelog()
-			maxLagMillisecondsThrottle := time.Duration(atomic.LoadInt64(&this.migrationContext.MaxLagMillisecondsThrottleThreshold)) * time.Millisecond
-			cutOverLockTimeout := time.Duration(this.migrationContext.CutOverLockTimeoutSeconds) * time.Second
-			if heartbeatLag > maxLagMillisecondsThrottle || heartbeatLag > cutOverLockTimeout {
-				this.migrationContext.Log.Debugf("current HeartbeatLag (%.2fs) is too high, it needs to be less than both --max-lag-millis (%.2fs) and --cut-over-lock-timeout-seconds (%.2fs) to continue", heartbeatLag.Seconds(), maxLagMillisecondsThrottle.Seconds(), cutOverLockTimeout.Seconds())
-				return true, nil
-			}
 			if this.migrationContext.PostponeCutOverFlagFile == "" {
 				return false, nil
 			}
@ -548,19 +517,19 @@ func (this *Migrator) cutOver() (err error) {
 			}
 		}
 	}
-
-	switch this.migrationContext.CutOverType {
-	case base.CutOverAtomic:
+	if this.migrationContext.CutOverType == base.CutOverAtomic {
 		// Atomic solution: we use low timeout and multiple attempts. But for
 		// each failed attempt, we throttle until replication lag is back to normal
-		err = this.atomicCutOver()
-	case base.CutOverTwoStep:
-		err = this.cutOverTwoStep()
-	default:
-		return this.migrationContext.Log.Fatalf("Unknown cut-over type: %d; should never get here!", this.migrationContext.CutOverType)
+		err := this.atomicCutOver()
+		this.handleCutOverResult(err)
+		return err
 	}
-	this.handleCutOverResult(err)
-	return err
+	if this.migrationContext.CutOverType == base.CutOverTwoStep {
+		err := this.cutOverTwoStep()
+		this.handleCutOverResult(err)
+		return err
+	}
+	return this.migrationContext.Log.Fatalf("Unknown cut-over type: %d; should never get here!", this.migrationContext.CutOverType)
 }

 // Inject the "AllEventsUpToLockProcessed" state hint, wait for it to appear in the binary logs,
@ -638,8 +607,12 @@ func (this *Migrator) atomicCutOver() (err error) {
 	defer atomic.StoreInt64(&this.migrationContext.InCutOverCriticalSectionFlag, 0)

 	okToUnlockTable := make(chan bool, 4)
+	var dropCutOverSentryTableOnce sync.Once
 	defer func() {
 		okToUnlockTable <- true
+		dropCutOverSentryTableOnce.Do(func() {
+			this.applier.DropAtomicCutOverSentryTableIfExists()
+		})
 	}()

 	atomic.StoreInt64(&this.migrationContext.AllEventsUpToLockProcessedInjectedFlag, 0)
@ -648,7 +621,7 @@ func (this *Migrator) atomicCutOver() (err error) {
 	tableLocked := make(chan error, 2)
 	tableUnlocked := make(chan error, 2)
 	go func() {
-		if err := this.applier.AtomicCutOverMagicLock(lockOriginalSessionIdChan, tableLocked, okToUnlockTable, tableUnlocked); err != nil {
+		if err := this.applier.AtomicCutOverMagicLock(lockOriginalSessionIdChan, tableLocked, okToUnlockTable, tableUnlocked, &dropCutOverSentryTableOnce); err != nil {
 			this.migrationContext.Log.Errore(err)
 		}
 	}()
@ -804,16 +777,17 @@ func (this *Migrator) initiateInspector() (err error) {
 }

 // initiateStatus sets and activates the printStatus() ticker
-func (this *Migrator) initiateStatus() {
+func (this *Migrator) initiateStatus() error {
 	this.printStatus(ForcePrintStatusAndHintRule)
-	ticker := time.NewTicker(time.Second)
-	defer ticker.Stop()
-	for range ticker.C {
+	statusTick := time.Tick(1 * time.Second)
+	for range statusTick {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
-			return
+			return nil
 		}
 		go this.printStatus(HeuristicPrintStatusRule)
 	}
+
+	return nil
 }

 // printMigrationStatusHint prints a detailed configuration dump, that is useful
@ -822,57 +796,57 @@ func (this *Migrator) initiateStatus() {
 // migration, and as response to the "status" interactive command.
 func (this *Migrator) printMigrationStatusHint(writers ...io.Writer) {
 	w := io.MultiWriter(writers...)
-	fmt.Fprintf(w, "# Migrating %s.%s; Ghost table is %s.%s\n",
+	fmt.Fprintln(w, fmt.Sprintf("# Migrating %s.%s; Ghost table is %s.%s",
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(this.migrationContext.OriginalTableName),
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(this.migrationContext.GetGhostTableName()),
-	)
-	fmt.Fprintf(w, "# Migrating %+v; inspecting %+v; executing on %+v\n",
+	))
+	fmt.Fprintln(w, fmt.Sprintf("# Migrating %+v; inspecting %+v; executing on %+v",
 		*this.applier.connectionConfig.ImpliedKey,
 		*this.inspector.connectionConfig.ImpliedKey,
 		this.migrationContext.Hostname,
-	)
-	fmt.Fprintf(w, "# Migration started at %+v\n",
+	))
+	fmt.Fprintln(w, fmt.Sprintf("# Migration started at %+v",
 		this.migrationContext.StartTime.Format(time.RubyDate),
-	)
+	))
 	maxLoad := this.migrationContext.GetMaxLoad()
 	criticalLoad := this.migrationContext.GetCriticalLoad()
-	fmt.Fprintf(w, "# chunk-size: %+v; max-lag-millis: %+vms; dml-batch-size: %+v; max-load: %s; critical-load: %s; nice-ratio: %f\n",
+	fmt.Fprintln(w, fmt.Sprintf("# chunk-size: %+v; max-lag-millis: %+vms; dml-batch-size: %+v; max-load: %s; critical-load: %s; nice-ratio: %f",
 		atomic.LoadInt64(&this.migrationContext.ChunkSize),
 		atomic.LoadInt64(&this.migrationContext.MaxLagMillisecondsThrottleThreshold),
 		atomic.LoadInt64(&this.migrationContext.DMLBatchSize),
 		maxLoad.String(),
 		criticalLoad.String(),
 		this.migrationContext.GetNiceRatio(),
-	)
+	))
 	if this.migrationContext.ThrottleFlagFile != "" {
 		setIndicator := ""
 		if base.FileExists(this.migrationContext.ThrottleFlagFile) {
 			setIndicator = "[set]"
 		}
-		fmt.Fprintf(w, "# throttle-flag-file: %+v %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# throttle-flag-file: %+v %+v",
 			this.migrationContext.ThrottleFlagFile, setIndicator,
-		)
+		))
 	}
 	if this.migrationContext.ThrottleAdditionalFlagFile != "" {
 		setIndicator := ""
 		if base.FileExists(this.migrationContext.ThrottleAdditionalFlagFile) {
 			setIndicator = "[set]"
 		}
-		fmt.Fprintf(w, "# throttle-additional-flag-file: %+v %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# throttle-additional-flag-file: %+v %+v",
 			this.migrationContext.ThrottleAdditionalFlagFile, setIndicator,
-		)
+		))
 	}
 	if throttleQuery := this.migrationContext.GetThrottleQuery(); throttleQuery != "" {
-		fmt.Fprintf(w, "# throttle-query: %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# throttle-query: %+v",
 			throttleQuery,
-		)
+		))
 	}
 	if throttleControlReplicaKeys := this.migrationContext.GetThrottleControlReplicaKeys(); throttleControlReplicaKeys.Len() > 0 {
-		fmt.Fprintf(w, "# throttle-control-replicas count: %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# throttle-control-replicas count: %+v",
 			throttleControlReplicaKeys.Len(),
-		)
+		))
 	}

 	if this.migrationContext.PostponeCutOverFlagFile != "" {
@ -880,111 +854,23 @@ func (this *Migrator) printMigrationStatusHint(writers ...io.Writer) {
 		if base.FileExists(this.migrationContext.PostponeCutOverFlagFile) {
 			setIndicator = "[set]"
 		}
-		fmt.Fprintf(w, "# postpone-cut-over-flag-file: %+v %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# postpone-cut-over-flag-file: %+v %+v",
 			this.migrationContext.PostponeCutOverFlagFile, setIndicator,
-		)
+		))
 	}
 	if this.migrationContext.PanicFlagFile != "" {
-		fmt.Fprintf(w, "# panic-flag-file: %+v\n",
+		fmt.Fprintln(w, fmt.Sprintf("# panic-flag-file: %+v",
 			this.migrationContext.PanicFlagFile,
-		)
+		))
 	}
-	fmt.Fprintf(w, "# Serving on unix socket: %+v\n",
+	fmt.Fprintln(w, fmt.Sprintf("# Serving on unix socket: %+v",
 		this.migrationContext.ServeSocketFile,
-	)
+	))
 	if this.migrationContext.ServeTCPPort != 0 {
-		fmt.Fprintf(w, "# Serving on TCP port: %+v\n", this.migrationContext.ServeTCPPort)
+		fmt.Fprintln(w, fmt.Sprintf("# Serving on TCP port: %+v", this.migrationContext.ServeTCPPort))
 	}
 }

-// getProgressPercent returns an estimate of migration progess as a percent.
-func (this *Migrator) getProgressPercent(rowsEstimate int64) (progressPct float64) {
-	progressPct = 100.0
-	if rowsEstimate > 0 {
-		progressPct *= float64(this.migrationContext.GetTotalRowsCopied()) / float64(rowsEstimate)
-	}
-	return progressPct
-}
-
-// getMigrationETA returns the estimated duration of the migration
-func (this *Migrator) getMigrationETA(rowsEstimate int64) (eta string, duration time.Duration) {
-	duration = time.Duration(base.ETAUnknown)
-	progressPct := this.getProgressPercent(rowsEstimate)
-	if progressPct >= 100.0 {
-		duration = 0
-	} else if progressPct >= 0.1 {
-		totalRowsCopied := this.migrationContext.GetTotalRowsCopied()
-		elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
-		totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
-		etaSeconds := totalExpectedSeconds - elapsedRowCopySeconds
-		if etaSeconds >= 0 {
-			duration = time.Duration(etaSeconds) * time.Second
-		} else {
-			duration = 0
-		}
-	}
-
-	switch duration {
-	case 0:
-		eta = "due"
-	case time.Duration(base.ETAUnknown):
-		eta = "N/A"
-	default:
-		eta = base.PrettifyDurationOutput(duration)
-	}
-
-	return eta, duration
-}
-
-// getMigrationStateAndETA returns the state and eta of the migration.
-func (this *Migrator) getMigrationStateAndETA(rowsEstimate int64) (state, eta string, etaDuration time.Duration) {
-	eta, etaDuration = this.getMigrationETA(rowsEstimate)
-	state = "migrating"
-	if atomic.LoadInt64(&this.migrationContext.CountingRowsFlag) > 0 && !this.migrationContext.ConcurrentCountTableRows {
-		state = "counting rows"
-	} else if atomic.LoadInt64(&this.migrationContext.IsPostponingCutOver) > 0 {
-		eta = "due"
-		state = "postponing cut-over"
-	} else if isThrottled, throttleReason, _ := this.migrationContext.IsThrottled(); isThrottled {
-		state = fmt.Sprintf("throttled, %s", throttleReason)
-	}
-	return state, eta, etaDuration
-}
-
-// shouldPrintStatus returns true when the migrator is due to print status info.
-func (this *Migrator) shouldPrintStatus(rule PrintStatusRule, elapsedSeconds int64, etaDuration time.Duration) (shouldPrint bool) {
-	if rule != HeuristicPrintStatusRule {
-		return true
-	}
-
-	etaSeconds := etaDuration.Seconds()
-	if elapsedSeconds <= 60 {
-		shouldPrint = true
-	} else if etaSeconds <= 60 {
-		shouldPrint = true
-	} else if etaSeconds <= 180 {
-		shouldPrint = (elapsedSeconds%5 == 0)
-	} else if elapsedSeconds <= 180 {
-		shouldPrint = (elapsedSeconds%5 == 0)
-	} else if this.migrationContext.TimeSincePointOfInterest().Seconds() <= 60 {
-		shouldPrint = (elapsedSeconds%5 == 0)
-	} else {
-		shouldPrint = (elapsedSeconds%30 == 0)
-	}
-
-	return shouldPrint
-}
-
-// shouldPrintMigrationStatus returns true when the migrator is due to print the migration status hint
-func (this *Migrator) shouldPrintMigrationStatusHint(rule PrintStatusRule, elapsedSeconds int64) (shouldPrint bool) {
-	if elapsedSeconds%600 == 0 {
-		shouldPrint = true
-	} else if rule == ForcePrintStatusAndHintRule {
-		shouldPrint = true
-	}
-	return shouldPrint
-}
-
 // printStatus prints the progress status, and optionally additionally detailed
 // dump of configuration.
 // `rule` indicates the type of output expected.
@ -1005,47 +891,95 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 		// and there is no further need to keep updating the value.
 		rowsEstimate = totalRowsCopied
 	}
-
+	var progressPct float64
+	if rowsEstimate == 0 {
+		progressPct = 100.0
+	} else {
+		progressPct = 100.0 * float64(totalRowsCopied) / float64(rowsEstimate)
+	}
 	// we take the opportunity to update migration context with progressPct
-	progressPct := this.getProgressPercent(rowsEstimate)
 	this.migrationContext.SetProgressPct(progressPct)
-
 	// Before status, let's see if we should print a nice reminder for what exactly we're doing here.
-	if this.shouldPrintMigrationStatusHint(rule, elapsedSeconds) {
+	shouldPrintMigrationStatusHint := (elapsedSeconds%600 == 0)
+	if rule == ForcePrintStatusAndHintRule {
+		shouldPrintMigrationStatusHint = true
+	}
+	if rule == ForcePrintStatusOnlyRule {
+		shouldPrintMigrationStatusHint = false
+	}
+	if shouldPrintMigrationStatusHint {
 		this.printMigrationStatusHint(writers...)
 	}

-	// Get state + ETA
-	state, eta, etaDuration := this.getMigrationStateAndETA(rowsEstimate)
-	this.migrationContext.SetETADuration(etaDuration)
+	var etaSeconds float64 = math.MaxFloat64
+	eta := "N/A"
+	if progressPct >= 100.0 {
+		eta = "due"
+	} else if progressPct >= 0.1 {
+		elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
+		totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
+		etaSeconds = totalExpectedSeconds - elapsedRowCopySeconds
+		if etaSeconds >= 0 {
+			etaDuration := time.Duration(etaSeconds) * time.Second
+			eta = base.PrettifyDurationOutput(etaDuration)
+		} else {
+			eta = "due"
+		}
+	}

-	if !this.shouldPrintStatus(rule, elapsedSeconds, etaDuration) {
+	state := "migrating"
+	if atomic.LoadInt64(&this.migrationContext.CountingRowsFlag) > 0 && !this.migrationContext.ConcurrentCountTableRows {
+		state = "counting rows"
+	} else if atomic.LoadInt64(&this.migrationContext.IsPostponingCutOver) > 0 {
+		eta = "due"
+		state = "postponing cut-over"
+	} else if isThrottled, throttleReason, _ := this.migrationContext.IsThrottled(); isThrottled {
+		state = fmt.Sprintf("throttled, %s", throttleReason)
+	}
+
+	shouldPrintStatus := false
+	if rule == HeuristicPrintStatusRule {
+		if elapsedSeconds <= 60 {
+			shouldPrintStatus = true
+		} else if etaSeconds <= 60 {
+			shouldPrintStatus = true
+		} else if etaSeconds <= 180 {
+			shouldPrintStatus = (elapsedSeconds%5 == 0)
+		} else if elapsedSeconds <= 180 {
+			shouldPrintStatus = (elapsedSeconds%5 == 0)
+		} else if this.migrationContext.TimeSincePointOfInterest().Seconds() <= 60 {
+			shouldPrintStatus = (elapsedSeconds%5 == 0)
+		} else {
+			shouldPrintStatus = (elapsedSeconds%30 == 0)
+		}
+	} else {
+		// Not heuristic
+		shouldPrintStatus = true
+	}
+	if !shouldPrintStatus {
 		return
 	}

 	currentBinlogCoordinates := *this.eventsStreamer.GetCurrentBinlogCoordinates()

-	status := fmt.Sprintf("Copy: %d/%d %.1f%%; Applied: %d; Backlog: %d/%d; Time: %+v(total), %+v(copy); streamer: %+v; Lag: %.2fs, HeartbeatLag: %.2fs, State: %s; ETA: %s",
+	status := fmt.Sprintf("Copy: %d/%d %.1f%%; Applied: %d; Backlog: %d/%d; Time: %+v(total), %+v(copy); streamer: %+v; Lag: %.2fs, State: %s; ETA: %s",
 		totalRowsCopied, rowsEstimate, progressPct,
 		atomic.LoadInt64(&this.migrationContext.TotalDMLEventsApplied),
 		len(this.applyEventsQueue), cap(this.applyEventsQueue),
 		base.PrettifyDurationOutput(elapsedTime), base.PrettifyDurationOutput(this.migrationContext.ElapsedRowCopyTime()),
 		currentBinlogCoordinates,
 		this.migrationContext.GetCurrentLagDuration().Seconds(),
-		this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds(),
 		state,
 		eta,
 	)
 	this.applier.WriteChangelog(
 		fmt.Sprintf("copy iteration %d at %d", this.migrationContext.GetIteration(), time.Now().Unix()),
-		state,
+		status,
 	)
 	w := io.MultiWriter(writers...)
 	fmt.Fprintln(w, status)
-	this.migrationContext.Log.Infof(status)

-	hooksStatusIntervalSec := this.migrationContext.HooksStatusIntervalSec
-	if hooksStatusIntervalSec > 0 && elapsedSeconds%hooksStatusIntervalSec == 0 {
+	if elapsedSeconds%60 == 0 {
 		this.hooksExecutor.onStatus(status)
 	}
 }
@ -1061,7 +995,7 @@ func (this *Migrator) initiateStreaming() error {
 		this.migrationContext.DatabaseName,
 		this.migrationContext.GetChangelogTableName(),
 		func(dmlEvent *binlog.BinlogDMLEvent) error {
-			return this.onChangelogEvent(dmlEvent)
+			return this.onChangelogStateEvent(dmlEvent)
 		},
 	)

@ -1075,9 +1009,8 @@ func (this *Migrator) initiateStreaming() error {
 	}()

 	go func() {
-		ticker := time.NewTicker(time.Second)
-		defer ticker.Stop()
-		for range ticker.C {
+		ticker := time.Tick(1 * time.Second)
+		for range ticker {
 			if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 				return
 			}
@ -1103,8 +1036,8 @@ func (this *Migrator) addDMLEventsListener() error {
 }

 // initiateThrottler kicks in the throttling collection and the throttling checks.
-func (this *Migrator) initiateThrottler() {
-	this.throttler = NewThrottler(this.migrationContext, this.applier, this.inspector, this.appVersion)
+func (this *Migrator) initiateThrottler() error {
+	this.throttler = NewThrottler(this.migrationContext, this.applier, this.inspector)

 	go this.throttler.initiateThrottlerCollection(this.firstThrottlingCollected)
 	this.migrationContext.Log.Infof("Waiting for first throttle metrics to be collected")
@ -1113,6 +1046,8 @@ func (this *Migrator) initiateThrottler() {
 	<-this.firstThrottlingCollected // other, general metrics
 	this.migrationContext.Log.Infof("First throttle metrics collected")
 	go this.throttler.initiateThrottlerChecks()
+
+	return nil
 }

 func (this *Migrator) initiateApplier() error {
@ -1137,14 +1072,6 @@ func (this *Migrator) initiateApplier() error {
 		return err
 	}

-	if this.migrationContext.OriginalTableAutoIncrement > 0 && !this.parser.IsAutoIncrementDefined() {
-		// Original table has AUTO_INCREMENT value and the -alter statement does not indicate any override,
-		// so we should copy AUTO_INCREMENT value onto our ghost table.
-		if err := this.applier.AlterGhostAutoIncrement(); err != nil {
-			this.migrationContext.Log.Errorf("Unable to ALTER ghost table AUTO_INCREMENT value, see further error details. Bailing out")
-			return err
-		}
-	}
 	this.applier.WriteChangelogState(string(GhostTableMigrated))
 	go this.applier.InitiateHeartbeat()
 	return nil
@ -1223,6 +1150,7 @@ func (this *Migrator) iterateChunks() error {
 		// Enqueue copy operation; to be executed by executeWriteFuncs()
 		this.copyRowsQueue <- copyRowsFunc
 	}
+	return nil
 }

 func (this *Migrator) onApplyEventStruct(eventStruct *applyEventStruct) error {
@ -1313,7 +1241,7 @@ func (this *Migrator) executeWriteFuncs() error {
 						if niceRatio := this.migrationContext.GetNiceRatio(); niceRatio > 0 {
 							copyRowsDuration := time.Since(copyRowsStartTime)
 							sleepTimeNanosecondFloat64 := niceRatio * float64(copyRowsDuration.Nanoseconds())
-							sleepTime := time.Duration(int64(sleepTimeNanosecondFloat64)) * time.Nanosecond
+							sleepTime := time.Duration(time.Duration(int64(sleepTimeNanosecondFloat64)) * time.Nanosecond)
 							time.Sleep(sleepTime)
 						}
 					}
@ -1328,17 +1256,13 @@ func (this *Migrator) executeWriteFuncs() error {
 			}
 		}
 	}
+	return nil
 }

 // finalCleanup takes actions at very end of migration, dropping tables etc.
 func (this *Migrator) finalCleanup() error {
 	atomic.StoreInt64(&this.migrationContext.CleanupImminentFlag, 1)

-	this.migrationContext.Log.Infof("Writing changelog state: %+v", Migrated)
-	if _, err := this.applier.WriteChangelogState(string(Migrated)); err != nil {
-		return err
-	}
-
 	if this.migrationContext.Noop {
 		if createTableStatement, err := this.inspector.showCreateTable(this.migrationContext.GetGhostTableName()); err == nil {
 			this.migrationContext.Log.Infof("New table structure follows")
--- a/go/logic/migrator_test.go
+++ b/go/logic/migrator_test.go
@ -1,256 +0,0 @@
-/*
-   Copyright 2022 GitHub Inc.
-         See https://github.com/github/gh-ost/blob/master/LICENSE
-*/
-
-package logic
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/openark/golib/tests"
-
-	"github.com/github/gh-ost/go/base"
-	"github.com/github/gh-ost/go/binlog"
-	"github.com/github/gh-ost/go/sql"
-)
-
-func TestMigratorOnChangelogEvent(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrator := NewMigrator(migrationContext, "1.2.3")
-
-	t.Run("heartbeat", func(t *testing.T) {
-		columnValues := sql.ToColumnValues([]interface{}{
-			123,
-			time.Now().Unix(),
-			"heartbeat",
-			"2022-08-16T00:45:10.52Z",
-		})
-		tests.S(t).ExpectNil(migrator.onChangelogEvent(&binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}))
-	})
-
-	t.Run("state-AllEventsUpToLockProcessed", func(t *testing.T) {
-		var wg sync.WaitGroup
-		wg.Add(1)
-		go func(wg *sync.WaitGroup) {
-			defer wg.Done()
-			es := <-migrator.applyEventsQueue
-			tests.S(t).ExpectNotNil(es)
-			tests.S(t).ExpectNotNil(es.writeFunc)
-		}(&wg)
-
-		columnValues := sql.ToColumnValues([]interface{}{
-			123,
-			time.Now().Unix(),
-			"state",
-			AllEventsUpToLockProcessed,
-		})
-		tests.S(t).ExpectNil(migrator.onChangelogEvent(&binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}))
-		wg.Wait()
-	})
-
-	t.Run("state-GhostTableMigrated", func(t *testing.T) {
-		go func() {
-			tests.S(t).ExpectTrue(<-migrator.ghostTableMigrated)
-		}()
-
-		columnValues := sql.ToColumnValues([]interface{}{
-			123,
-			time.Now().Unix(),
-			"state",
-			GhostTableMigrated,
-		})
-		tests.S(t).ExpectNil(migrator.onChangelogEvent(&binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}))
-	})
-
-	t.Run("state-Migrated", func(t *testing.T) {
-		columnValues := sql.ToColumnValues([]interface{}{
-			123,
-			time.Now().Unix(),
-			"state",
-			Migrated,
-		})
-		tests.S(t).ExpectNil(migrator.onChangelogEvent(&binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}))
-	})
-
-	t.Run("state-ReadMigrationRangeValues", func(t *testing.T) {
-		columnValues := sql.ToColumnValues([]interface{}{
-			123,
-			time.Now().Unix(),
-			"state",
-			ReadMigrationRangeValues,
-		})
-		tests.S(t).ExpectNil(migrator.onChangelogEvent(&binlog.BinlogDMLEvent{
-			DatabaseName:    "test",
-			DML:             binlog.InsertDML,
-			NewColumnValues: columnValues,
-		}))
-	})
-}
-
-func TestMigratorValidateStatement(t *testing.T) {
-	t.Run("add-column", func(t *testing.T) {
-		migrationContext := base.NewMigrationContext()
-		migrator := NewMigrator(migrationContext, "1.2.3")
-		tests.S(t).ExpectNil(migrator.parser.ParseAlterStatement(`ALTER TABLE test ADD test_new VARCHAR(64) NOT NULL`))
-
-		tests.S(t).ExpectNil(migrator.validateAlterStatement())
-		tests.S(t).ExpectEquals(len(migrator.migrationContext.DroppedColumnsMap), 0)
-	})
-
-	t.Run("drop-column", func(t *testing.T) {
-		migrationContext := base.NewMigrationContext()
-		migrator := NewMigrator(migrationContext, "1.2.3")
-		tests.S(t).ExpectNil(migrator.parser.ParseAlterStatement(`ALTER TABLE test DROP abc`))
-
-		tests.S(t).ExpectNil(migrator.validateAlterStatement())
-		tests.S(t).ExpectEquals(len(migrator.migrationContext.DroppedColumnsMap), 1)
-		_, exists := migrator.migrationContext.DroppedColumnsMap["abc"]
-		tests.S(t).ExpectTrue(exists)
-	})
-
-	t.Run("rename-column", func(t *testing.T) {
-		migrationContext := base.NewMigrationContext()
-		migrator := NewMigrator(migrationContext, "1.2.3")
-		tests.S(t).ExpectNil(migrator.parser.ParseAlterStatement(`ALTER TABLE test CHANGE test123 test1234 bigint unsigned`))
-
-		err := migrator.validateAlterStatement()
-		tests.S(t).ExpectNotNil(err)
-		tests.S(t).ExpectTrue(strings.HasPrefix(err.Error(), "gh-ost believes the ALTER statement renames columns"))
-		tests.S(t).ExpectEquals(len(migrator.migrationContext.DroppedColumnsMap), 0)
-	})
-
-	t.Run("rename-column-approved", func(t *testing.T) {
-		migrationContext := base.NewMigrationContext()
-		migrator := NewMigrator(migrationContext, "1.2.3")
-		migrator.migrationContext.ApproveRenamedColumns = true
-		tests.S(t).ExpectNil(migrator.parser.ParseAlterStatement(`ALTER TABLE test CHANGE test123 test1234 bigint unsigned`))
-
-		tests.S(t).ExpectNil(migrator.validateAlterStatement())
-		tests.S(t).ExpectEquals(len(migrator.migrationContext.DroppedColumnsMap), 0)
-	})
-
-	t.Run("rename-table", func(t *testing.T) {
-		migrationContext := base.NewMigrationContext()
-		migrator := NewMigrator(migrationContext, "1.2.3")
-		tests.S(t).ExpectNil(migrator.parser.ParseAlterStatement(`ALTER TABLE test RENAME TO test_new`))
-
-		err := migrator.validateAlterStatement()
-		tests.S(t).ExpectNotNil(err)
-		tests.S(t).ExpectTrue(errors.Is(err, ErrMigratorUnsupportedRenameAlter))
-		tests.S(t).ExpectEquals(len(migrator.migrationContext.DroppedColumnsMap), 0)
-	})
-}
-
-func TestMigratorCreateFlagFiles(t *testing.T) {
-	tmpdir, err := os.MkdirTemp("", t.Name())
-	if err != nil {
-		panic(err)
-	}
-	defer os.RemoveAll(tmpdir)
-
-	migrationContext := base.NewMigrationContext()
-	migrationContext.PostponeCutOverFlagFile = filepath.Join(tmpdir, "cut-over.flag")
-	migrator := NewMigrator(migrationContext, "1.2.3")
-	tests.S(t).ExpectNil(migrator.createFlagFiles())
-	tests.S(t).ExpectNil(migrator.createFlagFiles()) // twice to test already-exists
-
-	_, err = os.Stat(migrationContext.PostponeCutOverFlagFile)
-	tests.S(t).ExpectNil(err)
-}
-
-func TestMigratorGetProgressPercent(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrator := NewMigrator(migrationContext, "1.2.3")
-
-	{
-		tests.S(t).ExpectEquals(migrator.getProgressPercent(0), float64(100.0))
-	}
-	{
-		migrationContext.TotalRowsCopied = 250
-		tests.S(t).ExpectEquals(migrator.getProgressPercent(1000), float64(25.0))
-	}
-}
-
-func TestMigratorGetMigrationStateAndETA(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrator := NewMigrator(migrationContext, "1.2.3")
-	now := time.Now()
-	migrationContext.RowCopyStartTime = now.Add(-time.Minute)
-	migrationContext.RowCopyEndTime = now
-
-	{
-		migrationContext.TotalRowsCopied = 456
-		state, eta, etaDuration := migrator.getMigrationStateAndETA(123456)
-		tests.S(t).ExpectEquals(state, "migrating")
-		tests.S(t).ExpectEquals(eta, "4h29m44s")
-		tests.S(t).ExpectEquals(etaDuration.String(), "4h29m44s")
-	}
-	{
-		migrationContext.TotalRowsCopied = 456
-		state, eta, etaDuration := migrator.getMigrationStateAndETA(456)
-		tests.S(t).ExpectEquals(state, "migrating")
-		tests.S(t).ExpectEquals(eta, "due")
-		tests.S(t).ExpectEquals(etaDuration.String(), "0s")
-	}
-	{
-		migrationContext.TotalRowsCopied = 123456
-		state, eta, etaDuration := migrator.getMigrationStateAndETA(456)
-		tests.S(t).ExpectEquals(state, "migrating")
-		tests.S(t).ExpectEquals(eta, "due")
-		tests.S(t).ExpectEquals(etaDuration.String(), "0s")
-	}
-	{
-		atomic.StoreInt64(&migrationContext.CountingRowsFlag, 1)
-		state, eta, etaDuration := migrator.getMigrationStateAndETA(123456)
-		tests.S(t).ExpectEquals(state, "counting rows")
-		tests.S(t).ExpectEquals(eta, "due")
-		tests.S(t).ExpectEquals(etaDuration.String(), "0s")
-	}
-	{
-		atomic.StoreInt64(&migrationContext.CountingRowsFlag, 0)
-		atomic.StoreInt64(&migrationContext.IsPostponingCutOver, 1)
-		state, eta, etaDuration := migrator.getMigrationStateAndETA(123456)
-		tests.S(t).ExpectEquals(state, "postponing cut-over")
-		tests.S(t).ExpectEquals(eta, "due")
-		tests.S(t).ExpectEquals(etaDuration.String(), "0s")
-	}
-}
-
-func TestMigratorShouldPrintStatus(t *testing.T) {
-	migrationContext := base.NewMigrationContext()
-	migrator := NewMigrator(migrationContext, "1.2.3")
-
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(NoPrintStatusRule, 10, time.Second))                  // test 'rule != HeuristicPrintStatusRule' return
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 10, time.Second))           // test 'etaDuration.Seconds() <= 60'
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 90, time.Second))           // test 'etaDuration.Seconds() <= 60' again
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 90, time.Minute))           // test 'etaDuration.Seconds() <= 180'
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 60, 90*time.Second))        // test 'elapsedSeconds <= 180'
-	tests.S(t).ExpectFalse(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 61, 90*time.Second))       // test 'elapsedSeconds <= 180'
-	tests.S(t).ExpectFalse(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 99, 210*time.Second))      // test 'elapsedSeconds <= 180'
-	tests.S(t).ExpectFalse(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 12345, 86400*time.Second)) // test 'else'
-	tests.S(t).ExpectTrue(migrator.shouldPrintStatus(HeuristicPrintStatusRule, 30030, 86400*time.Second))  // test 'else' again
-}
--- a/go/logic/server.go
+++ b/go/logic/server.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -122,6 +122,8 @@ func (this *Server) onServerCommand(command string, writer *bufio.Writer) (err e

 // applyServerCommand parses and executes commands by user
 func (this *Server) applyServerCommand(command string, writer *bufio.Writer) (printStatusRule PrintStatusRule, err error) {
+	printStatusRule = NoPrintStatusRule
+
 	tokens := strings.SplitN(command, "=", 2)
 	command = strings.TrimSpace(tokens[0])
 	arg := ""
@ -132,7 +134,7 @@ func (this *Server) applyServerCommand(command string, writer *bufio.Writer) (pr
 		}
 	}
 	argIsQuestion := (arg == "?")
-	throttleHint := "# Note: you may only throttle for as long as your binary logs are not purged"
+	throttleHint := "# Note: you may only throttle for as long as your binary logs are not purged\n"

 	if err := this.hooksExecutor.onInteractiveCommand(command); err != nil {
 		return NoPrintStatusRule, err
@ -144,9 +146,7 @@ func (this *Server) applyServerCommand(command string, writer *bufio.Writer) (pr
 			fmt.Fprint(writer, `available commands:
 status                               # Print a detailed status message
 sup                                  # Print a short status message
-coordinates                          # Print the currently inspected coordinates
-applier                              # Print the hostname of the applier
-inspector                            # Print the hostname of the inspector
+coordinates													 # Print the currently inspected coordinates
 chunk-size=<newsize>                 # Set a new chunk-size
 dml-batch-size=<newsize>             # Set a new dml-batch-size
 nice-ratio=<ratio>                   # Set a new nice-ratio, immediate sleep after each row-copy operation, float (examples: 0 is aggressive, 0.7 adds 70% runtime, 1.0 doubles runtime, 2.0 triples runtime, ...)
@ -177,22 +177,6 @@ help                                 # This message
 			}
 			return NoPrintStatusRule, fmt.Errorf("coordinates are read-only")
 		}
-	case "applier":
-		if this.migrationContext.ApplierConnectionConfig != nil && this.migrationContext.ApplierConnectionConfig.ImpliedKey != nil {
-			fmt.Fprintf(writer, "Host: %s, Version: %s\n",
-				this.migrationContext.ApplierConnectionConfig.ImpliedKey.String(),
-				this.migrationContext.ApplierMySQLVersion,
-			)
-		}
-		return NoPrintStatusRule, nil
-	case "inspector":
-		if this.migrationContext.InspectorConnectionConfig != nil && this.migrationContext.InspectorConnectionConfig.ImpliedKey != nil {
-			fmt.Fprintf(writer, "Host: %s, Version: %s\n",
-				this.migrationContext.InspectorConnectionConfig.ImpliedKey.String(),
-				this.migrationContext.InspectorMySQLVersion,
-			)
-		}
-		return NoPrintStatusRule, nil
 	case "chunk-size":
 		{
 			if argIsQuestion {
@ -280,7 +264,7 @@ help                                 # This message
 				return NoPrintStatusRule, nil
 			}
 			this.migrationContext.SetThrottleQuery(arg)
-			fmt.Fprintln(writer, throttleHint)
+			fmt.Fprintf(writer, throttleHint)
 			return ForcePrintStatusAndHintRule, nil
 		}
 	case "throttle-http":
@ -290,7 +274,7 @@ help                                 # This message
 				return NoPrintStatusRule, nil
 			}
 			this.migrationContext.SetThrottleHTTP(arg)
-			fmt.Fprintln(writer, throttleHint)
+			fmt.Fprintf(writer, throttleHint)
 			return ForcePrintStatusAndHintRule, nil
 		}
 	case "throttle-control-replicas":
@ -313,7 +297,7 @@ help                                 # This message
 				return NoPrintStatusRule, err
 			}
 			atomic.StoreInt64(&this.migrationContext.ThrottleCommandedByUser, 1)
-			fmt.Fprintln(writer, throttleHint)
+			fmt.Fprintf(writer, throttleHint)
 			return ForcePrintStatusAndHintRule, nil
 		}
 	case "no-throttle", "unthrottle", "resume", "continue":
--- a/go/logic/streamer.go
+++ b/go/logic/streamer.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -16,7 +16,7 @@ import (
 	"github.com/github/gh-ost/go/binlog"
 	"github.com/github/gh-ost/go/mysql"

-	"github.com/openark/golib/sqlutils"
+	"github.com/outbrain/golib/sqlutils"
 )

 type BinlogEventListener struct {
@ -42,7 +42,6 @@ type EventsStreamer struct {
 	listenersMutex           *sync.Mutex
 	eventsChannel            chan *binlog.BinlogEntry
 	binlogReader             *binlog.GoMySQLReader
-	name                     string
 }

 func NewEventsStreamer(migrationContext *base.MigrationContext) *EventsStreamer {
@ -52,13 +51,13 @@ func NewEventsStreamer(migrationContext *base.MigrationContext) *EventsStreamer
 		listeners:        [](*BinlogEventListener){},
 		listenersMutex:   &sync.Mutex{},
 		eventsChannel:    make(chan *binlog.BinlogEntry, EventsChannelBufferSize),
-		name:             "streamer",
 	}
 }

 // AddListener registers a new listener for binlog events, on a per-table basis
 func (this *EventsStreamer) AddListener(
 	async bool, databaseName string, tableName string, onDmlEvent func(event *binlog.BinlogDMLEvent) error) (err error) {
+
 	this.listenersMutex.Lock()
 	defer this.listenersMutex.Unlock()

@ -86,10 +85,10 @@ func (this *EventsStreamer) notifyListeners(binlogEvent *binlog.BinlogDMLEvent)

 	for _, listener := range this.listeners {
 		listener := listener
-		if !strings.EqualFold(listener.databaseName, binlogEvent.DatabaseName) {
+		if strings.ToLower(listener.databaseName) != strings.ToLower(binlogEvent.DatabaseName) {
 			continue
 		}
-		if !strings.EqualFold(listener.tableName, binlogEvent.TableName) {
+		if strings.ToLower(listener.tableName) != strings.ToLower(binlogEvent.TableName) {
 			continue
 		}
 		if listener.async {
@ -107,7 +106,7 @@ func (this *EventsStreamer) InitDBConnections() (err error) {
 	if this.db, _, err = mysql.GetDB(this.migrationContext.Uuid, EventsStreamerUri); err != nil {
 		return err
 	}
-	if _, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name); err != nil {
+	if _, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext); err != nil {
 		return err
 	}
 	if err := this.readCurrentBinlogCoordinates(); err != nil {
@ -122,7 +121,10 @@ func (this *EventsStreamer) InitDBConnections() (err error) {

 // initBinlogReader creates and connects the reader: we hook up to a MySQL server as a replica
 func (this *EventsStreamer) initBinlogReader(binlogCoordinates *mysql.BinlogCoordinates) error {
-	goMySQLReader := binlog.NewGoMySQLReader(this.migrationContext)
+	goMySQLReader, err := binlog.NewGoMySQLReader(this.migrationContext)
+	if err != nil {
+		return err
+	}
 	if err := goMySQLReader.ConnectBinlogStreamer(*binlogCoordinates); err != nil {
 		return err
 	}
@ -216,4 +218,5 @@ func (this *EventsStreamer) Close() (err error) {

 func (this *EventsStreamer) Teardown() {
 	this.db.Close()
+	return
 }
--- a/go/logic/throttler.go
+++ b/go/logic/throttler.go
@ -1,12 +1,11 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

 package logic

 import (
-	"context"
 	"fmt"
 	"net/http"
 	"strings"
@ -43,22 +42,16 @@ const frenoMagicHint = "freno"
 // Throttler collects metrics related to throttling and makes informed decision
 // whether throttling should take place.
 type Throttler struct {
-	appVersion        string
 	migrationContext  *base.MigrationContext
 	applier           *Applier
-	httpClient        *http.Client
-	httpClientTimeout time.Duration
 	inspector         *Inspector
 	finishedMigrating int64
 }

-func NewThrottler(migrationContext *base.MigrationContext, applier *Applier, inspector *Inspector, appVersion string) *Throttler {
+func NewThrottler(migrationContext *base.MigrationContext, applier *Applier, inspector *Inspector) *Throttler {
 	return &Throttler{
-		appVersion:        appVersion,
 		migrationContext:  migrationContext,
 		applier:           applier,
-		httpClient:        &http.Client{},
-		httpClientTimeout: time.Duration(migrationContext.ThrottleHTTPTimeoutMillis) * time.Millisecond,
 		inspector:         inspector,
 		finishedMigrating: 0,
 	}
@ -168,9 +161,8 @@ func (this *Throttler) collectReplicationLag(firstThrottlingCollected chan<- boo
 	collectFunc()
 	firstThrottlingCollected <- true

-	ticker := time.NewTicker(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
-	defer ticker.Stop()
-	for range ticker.C {
+	ticker := time.Tick(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
+	for range ticker {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 			return
 		}
@ -180,6 +172,7 @@ func (this *Throttler) collectReplicationLag(firstThrottlingCollected chan<- boo

 // collectControlReplicasLag polls all the control replicas to get maximum lag value
 func (this *Throttler) collectControlReplicasLag() {
+
 	if atomic.LoadInt64(&this.migrationContext.HibernateUntil) > 0 {
 		return
 	}
@ -195,12 +188,9 @@ func (this *Throttler) collectControlReplicasLag() {
 		dbUri := connectionConfig.GetDBUri("information_schema")

 		var heartbeatValue string
-		db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri)
-		if err != nil {
+		if db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri); err != nil {
 			return lag, err
-		}
-
-		if err := db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
+		} else if err = db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
 			return lag, err
 		}

@ -244,14 +234,12 @@ func (this *Throttler) collectControlReplicasLag() {
 		}
 		this.migrationContext.SetControlReplicasLagResult(readControlReplicasLag())
 	}
-
+	aggressiveTicker := time.Tick(100 * time.Millisecond)
 	relaxedFactor := 10
 	counter := 0
 	shouldReadLagAggressively := false

-	ticker := time.NewTicker(100 * time.Millisecond)
-	defer ticker.Stop()
-	for range ticker.C {
+	for range aggressiveTicker {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 			return
 		}
@ -294,22 +282,10 @@ func (this *Throttler) collectThrottleHTTPStatus(firstThrottlingCollected chan<-
 		if url == "" {
 			return true, nil
 		}
-
-		ctx, cancel := context.WithTimeout(context.Background(), this.httpClientTimeout)
-		defer cancel()
-
-		req, err := http.NewRequestWithContext(ctx, http.MethodHead, url, nil)
+		resp, err := http.Head(url)
 		if err != nil {
 			return false, err
 		}
-		req.Header.Set("User-Agent", fmt.Sprintf("gh-ost/%s", this.appVersion))
-
-		resp, err := this.httpClient.Do(req)
-		if err != nil {
-			return false, err
-		}
-		defer resp.Body.Close()
-
 		atomic.StoreInt64(&this.migrationContext.ThrottleHTTPStatusCode, int64(resp.StatusCode))
 		return false, nil
 	}
@ -324,10 +300,8 @@ func (this *Throttler) collectThrottleHTTPStatus(firstThrottlingCollected chan<-

 	firstThrottlingCollected <- true

-	collectInterval := time.Duration(this.migrationContext.ThrottleHTTPIntervalMillis) * time.Millisecond
-	ticker := time.NewTicker(collectInterval)
-	defer ticker.Stop()
-	for range ticker.C {
+	ticker := time.Tick(100 * time.Millisecond)
+	for range ticker {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 			return
 		}
@ -446,9 +420,8 @@ func (this *Throttler) initiateThrottlerCollection(firstThrottlingCollected chan
 		this.collectGeneralThrottleMetrics()
 		firstThrottlingCollected <- true

-		ticker := time.NewTicker(time.Second)
-		defer ticker.Stop()
-		for range ticker.C {
+		throttlerMetricsTick := time.Tick(1 * time.Second)
+		for range throttlerMetricsTick {
 			if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 				return
 			}
@ -459,7 +432,9 @@ func (this *Throttler) initiateThrottlerCollection(firstThrottlingCollected chan
 }

 // initiateThrottlerChecks initiates the throttle ticker and sets the basic behavior of throttling.
-func (this *Throttler) initiateThrottlerChecks() {
+func (this *Throttler) initiateThrottlerChecks() error {
+	throttlerTick := time.Tick(100 * time.Millisecond)
+
 	throttlerFunction := func() {
 		alreadyThrottling, currentReason, _ := this.migrationContext.IsThrottled()
 		shouldThrottle, throttleReason, throttleReasonHint := this.shouldThrottle()
@ -476,15 +451,14 @@ func (this *Throttler) initiateThrottlerChecks() {
 		this.migrationContext.SetThrottled(shouldThrottle, throttleReason, throttleReasonHint)
 	}
 	throttlerFunction()
-
-	ticker := time.NewTicker(100 * time.Millisecond)
-	defer ticker.Stop()
-	for range ticker.C {
+	for range throttlerTick {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
-			return
+			return nil
 		}
 		throttlerFunction()
 	}
+
+	return nil
 }

 // throttle sees if throttling needs take place, and if so, continuously sleeps (blocks)
--- a/go/mysql/binlog.go
+++ b/go/mysql/binlog.go
@ -1,21 +1,36 @@
 /*
   Copyright 2015 Shlomi Noach, courtesy Booking.com
-   Copyright 2022 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

 package mysql

 import (
+	"errors"
 	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
 )

+var detachPattern *regexp.Regexp
+
+func init() {
+	detachPattern, _ = regexp.Compile(`//([^/:]+):([\d]+)`) // e.g. `//binlog.01234:567890`
+}
+
+type BinlogType int
+
+const (
+	BinaryLog BinlogType = iota
+	RelayLog
+)
+
 // BinlogCoordinates described binary log coordinates in the form of log file & log position.
 type BinlogCoordinates struct {
 	LogFile string
 	LogPos  int64
+	Type    BinlogType
 }

 // ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306
@ -47,7 +62,7 @@ func (this *BinlogCoordinates) Equals(other *BinlogCoordinates) bool {
 	if other == nil {
 		return false
 	}
-	return this.LogFile == other.LogFile && this.LogPos == other.LogPos
+	return this.LogFile == other.LogFile && this.LogPos == other.LogPos && this.Type == other.Type
 }

 // IsEmpty returns true if the log file is empty, unnamed
@ -72,5 +87,76 @@ func (this *BinlogCoordinates) SmallerThanOrEquals(other *BinlogCoordinates) boo
 	if this.SmallerThan(other) {
 		return true
 	}
-	return this.LogFile == other.LogFile && this.LogPos == other.LogPos
+	return this.LogFile == other.LogFile && this.LogPos == other.LogPos // No Type comparison
+}
+
+// FileSmallerThan returns true if this coordinate's file is strictly smaller than the other's.
+func (this *BinlogCoordinates) FileSmallerThan(other *BinlogCoordinates) bool {
+	return this.LogFile < other.LogFile
+}
+
+// FileNumberDistance returns the numeric distance between this coordinate's file number and the other's.
+// Effectively it means "how many rotates/FLUSHes would make these coordinates's file reach the other's"
+func (this *BinlogCoordinates) FileNumberDistance(other *BinlogCoordinates) int {
+	thisNumber, _ := this.FileNumber()
+	otherNumber, _ := other.FileNumber()
+	return otherNumber - thisNumber
+}
+
+// FileNumber returns the numeric value of the file, and the length in characters representing the number in the filename.
+// Example: FileNumber() of mysqld.log.000789 is (789, 6)
+func (this *BinlogCoordinates) FileNumber() (int, int) {
+	tokens := strings.Split(this.LogFile, ".")
+	numPart := tokens[len(tokens)-1]
+	numLen := len(numPart)
+	fileNum, err := strconv.Atoi(numPart)
+	if err != nil {
+		return 0, 0
+	}
+	return fileNum, numLen
+}
+
+// PreviousFileCoordinatesBy guesses the filename of the previous binlog/relaylog, by given offset (number of files back)
+func (this *BinlogCoordinates) PreviousFileCoordinatesBy(offset int) (BinlogCoordinates, error) {
+	result := BinlogCoordinates{LogPos: 0, Type: this.Type}
+
+	fileNum, numLen := this.FileNumber()
+	if fileNum == 0 {
+		return result, errors.New("Log file number is zero, cannot detect previous file")
+	}
+	newNumStr := fmt.Sprintf("%d", (fileNum - offset))
+	newNumStr = strings.Repeat("0", numLen-len(newNumStr)) + newNumStr
+
+	tokens := strings.Split(this.LogFile, ".")
+	tokens[len(tokens)-1] = newNumStr
+	result.LogFile = strings.Join(tokens, ".")
+	return result, nil
+}
+
+// PreviousFileCoordinates guesses the filename of the previous binlog/relaylog
+func (this *BinlogCoordinates) PreviousFileCoordinates() (BinlogCoordinates, error) {
+	return this.PreviousFileCoordinatesBy(1)
+}
+
+// PreviousFileCoordinates guesses the filename of the previous binlog/relaylog
+func (this *BinlogCoordinates) NextFileCoordinates() (BinlogCoordinates, error) {
+	result := BinlogCoordinates{LogPos: 0, Type: this.Type}
+
+	fileNum, numLen := this.FileNumber()
+	newNumStr := fmt.Sprintf("%d", (fileNum + 1))
+	newNumStr = strings.Repeat("0", numLen-len(newNumStr)) + newNumStr
+
+	tokens := strings.Split(this.LogFile, ".")
+	tokens[len(tokens)-1] = newNumStr
+	result.LogFile = strings.Join(tokens, ".")
+	return result, nil
+}
+
+// FileSmallerThan returns true if this coordinate's file is strictly smaller than the other's.
+func (this *BinlogCoordinates) DetachedCoordinates() (isDetached bool, detachedLogFile string, detachedLogPos string) {
+	detachedCoordinatesSubmatch := detachPattern.FindStringSubmatch(this.LogFile)
+	if len(detachedCoordinatesSubmatch) == 0 {
+		return false, "", ""
+	}
+	return true, detachedCoordinatesSubmatch[1], detachedCoordinatesSubmatch[2]
 }
--- a/go/mysql/binlog_test.go
+++ b/go/mysql/binlog_test.go
@ -8,8 +8,8 @@ package mysql
 import (
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
@ -37,6 +37,57 @@ func TestBinlogCoordinates(t *testing.T) {
 	test.S(t).ExpectTrue(c1.SmallerThanOrEquals(&c3))
 }

+func TestBinlogNext(t *testing.T) {
+	c1 := BinlogCoordinates{LogFile: "mysql-bin.00017", LogPos: 104}
+	cres, err := c1.NextFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql-bin.00018")
+
+	c2 := BinlogCoordinates{LogFile: "mysql-bin.00099", LogPos: 104}
+	cres, err = c2.NextFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql-bin.00100")
+
+	c3 := BinlogCoordinates{LogFile: "mysql.00.prod.com.00099", LogPos: 104}
+	cres, err = c3.NextFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql.00.prod.com.00100")
+}
+
+func TestBinlogPrevious(t *testing.T) {
+	c1 := BinlogCoordinates{LogFile: "mysql-bin.00017", LogPos: 104}
+	cres, err := c1.PreviousFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql-bin.00016")
+
+	c2 := BinlogCoordinates{LogFile: "mysql-bin.00100", LogPos: 104}
+	cres, err = c2.PreviousFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql-bin.00099")
+
+	c3 := BinlogCoordinates{LogFile: "mysql.00.prod.com.00100", LogPos: 104}
+	cres, err = c3.PreviousFileCoordinates()
+
+	test.S(t).ExpectNil(err)
+	test.S(t).ExpectEquals(c1.Type, cres.Type)
+	test.S(t).ExpectEquals(cres.LogFile, "mysql.00.prod.com.00099")
+
+	c4 := BinlogCoordinates{LogFile: "mysql.00.prod.com.00000", LogPos: 104}
+	_, err = c4.PreviousFileCoordinates()
+
+	test.S(t).ExpectNotNil(err)
+}
+
 func TestBinlogCoordinatesAsKey(t *testing.T) {
 	m := make(map[BinlogCoordinates]bool)

@ -52,3 +103,20 @@ func TestBinlogCoordinatesAsKey(t *testing.T) {

 	test.S(t).ExpectEquals(len(m), 3)
 }
+
+func TestBinlogFileNumber(t *testing.T) {
+	c1 := BinlogCoordinates{LogFile: "mysql-bin.00017", LogPos: 104}
+	c2 := BinlogCoordinates{LogFile: "mysql-bin.00022", LogPos: 104}
+
+	test.S(t).ExpectEquals(c1.FileNumberDistance(&c1), 0)
+	test.S(t).ExpectEquals(c1.FileNumberDistance(&c2), 5)
+	test.S(t).ExpectEquals(c2.FileNumberDistance(&c1), -5)
+}
+
+func TestBinlogFileNumberDistance(t *testing.T) {
+	c1 := BinlogCoordinates{LogFile: "mysql-bin.00017", LogPos: 104}
+	fileNum, numLen := c1.FileNumber()
+
+	test.S(t).ExpectEquals(fileNum, 17)
+	test.S(t).ExpectEquals(numLen, 5)
+}
--- a/go/mysql/connection.go
+++ b/go/mysql/connection.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -12,7 +12,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net"
-	"strings"

 	"github.com/go-sql-driver/mysql"
 )
@ -23,13 +22,12 @@ const (

 // ConnectionConfig is the minimal configuration required to connect to a MySQL server
 type ConnectionConfig struct {
-	Key                  InstanceKey
-	User                 string
-	Password             string
-	ImpliedKey           *InstanceKey
-	tlsConfig            *tls.Config
-	Timeout              float64
-	TransactionIsolation string
+	Key        InstanceKey
+	User       string
+	Password   string
+	ImpliedKey *InstanceKey
+	tlsConfig  *tls.Config
+	Timeout    float64
 }

 func NewConnectionConfig() *ConnectionConfig {
@ -43,12 +41,11 @@ func NewConnectionConfig() *ConnectionConfig {
 // DuplicateCredentials creates a new connection config with given key and with same credentials as this config
 func (this *ConnectionConfig) DuplicateCredentials(key InstanceKey) *ConnectionConfig {
 	config := &ConnectionConfig{
-		Key:                  key,
-		User:                 this.User,
-		Password:             this.Password,
-		tlsConfig:            this.tlsConfig,
-		Timeout:              this.Timeout,
-		TransactionIsolation: this.TransactionIsolation,
+		Key:       key,
+		User:      this.User,
+		Password:  this.Password,
+		tlsConfig: this.tlsConfig,
+		Timeout:   this.Timeout,
 	}
 	config.ImpliedKey = &config.Key
 	return config
@ -95,7 +92,6 @@ func (this *ConnectionConfig) UseTLS(caCertificatePath, clientCertificate, clien
 	}

 	this.tlsConfig = &tls.Config{
-		ServerName:         this.Key.Hostname,
 		Certificates:       certs,
 		RootCAs:            rootCertPool,
 		InsecureSkipVerify: allowInsecure,
@ -115,23 +111,12 @@ func (this *ConnectionConfig) GetDBUri(databaseName string) string {
 		// Wrap IPv6 literals in square brackets
 		hostname = fmt.Sprintf("[%s]", hostname)
 	}
-
+	interpolateParams := true
 	// go-mysql-driver defaults to false if tls param is not provided; explicitly setting here to
 	// simplify construction of the DSN below.
 	tlsOption := "false"
 	if this.tlsConfig != nil {
 		tlsOption = TLS_CONFIG_KEY
 	}
-	connectionParams := []string{
-		"autocommit=true",
-		"charset=utf8mb4,utf8,latin1",
-		"interpolateParams=true",
-		fmt.Sprintf("tls=%s", tlsOption),
-		fmt.Sprintf("transaction_isolation=%q", this.TransactionIsolation),
-		fmt.Sprintf("timeout=%fs", this.Timeout),
-		fmt.Sprintf("readTimeout=%fs", this.Timeout),
-		fmt.Sprintf("writeTimeout=%fs", this.Timeout),
-	}
-
-	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?%s", this.User, this.Password, hostname, this.Key.Port, databaseName, strings.Join(connectionParams, "&"))
+	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?timeout=%fs&readTimeout=%fs&writeTimeout=%fs&interpolateParams=%t&autocommit=true&charset=utf8mb4,utf8,latin1&tls=%s", this.User, this.Password, hostname, this.Key.Port, databaseName, this.Timeout, this.Timeout, this.Timeout, interpolateParams, tlsOption)
 }
--- a/go/mysql/connection_test.go
+++ b/go/mysql/connection_test.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -9,12 +9,8 @@ import (
 	"crypto/tls"
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
-)
-
-const (
-	transactionIsolation = "REPEATABLE-READ"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
@ -29,7 +25,6 @@ func TestNewConnectionConfig(t *testing.T) {
 	test.S(t).ExpectEquals(c.ImpliedKey.Port, 0)
 	test.S(t).ExpectEquals(c.User, "")
 	test.S(t).ExpectEquals(c.Password, "")
-	test.S(t).ExpectEquals(c.TransactionIsolation, "")
 }

 func TestDuplicateCredentials(t *testing.T) {
@ -41,7 +36,6 @@ func TestDuplicateCredentials(t *testing.T) {
 		InsecureSkipVerify: true,
 		ServerName:         "feathers",
 	}
-	c.TransactionIsolation = transactionIsolation

 	dup := c.DuplicateCredentials(InstanceKey{Hostname: "otherhost", Port: 3310})
 	test.S(t).ExpectEquals(dup.Key.Hostname, "otherhost")
@ -51,7 +45,6 @@ func TestDuplicateCredentials(t *testing.T) {
 	test.S(t).ExpectEquals(dup.User, "gromit")
 	test.S(t).ExpectEquals(dup.Password, "penguin")
 	test.S(t).ExpectEquals(dup.tlsConfig, c.tlsConfig)
-	test.S(t).ExpectEquals(dup.TransactionIsolation, c.TransactionIsolation)
 }

 func TestDuplicate(t *testing.T) {
@ -59,7 +52,6 @@ func TestDuplicate(t *testing.T) {
 	c.Key = InstanceKey{Hostname: "myhost", Port: 3306}
 	c.User = "gromit"
 	c.Password = "penguin"
-	c.TransactionIsolation = transactionIsolation

 	dup := c.Duplicate()
 	test.S(t).ExpectEquals(dup.Key.Hostname, "myhost")
@ -68,7 +60,6 @@ func TestDuplicate(t *testing.T) {
 	test.S(t).ExpectEquals(dup.ImpliedKey.Port, 3306)
 	test.S(t).ExpectEquals(dup.User, "gromit")
 	test.S(t).ExpectEquals(dup.Password, "penguin")
-	test.S(t).ExpectEquals(dup.TransactionIsolation, transactionIsolation)
 }

 func TestGetDBUri(t *testing.T) {
@ -76,11 +67,9 @@ func TestGetDBUri(t *testing.T) {
 	c.Key = InstanceKey{Hostname: "myhost", Port: 3306}
 	c.User = "gromit"
 	c.Password = "penguin"
-	c.Timeout = 1.2345
-	c.TransactionIsolation = transactionIsolation

 	uri := c.GetDBUri("test")
-	test.S(t).ExpectEquals(uri, `gromit:penguin@tcp(myhost:3306)/test?autocommit=true&charset=utf8mb4,utf8,latin1&interpolateParams=true&tls=false&transaction_isolation="REPEATABLE-READ"&timeout=1.234500s&readTimeout=1.234500s&writeTimeout=1.234500s`)
+	test.S(t).ExpectEquals(uri, "gromit:penguin@tcp(myhost:3306)/test?timeout=0.000000s&readTimeout=0.000000s&writeTimeout=0.000000s&interpolateParams=true&autocommit=true&charset=utf8mb4,utf8,latin1&tls=false")
 }

 func TestGetDBUriWithTLSSetup(t *testing.T) {
@ -88,10 +77,8 @@ func TestGetDBUriWithTLSSetup(t *testing.T) {
 	c.Key = InstanceKey{Hostname: "myhost", Port: 3306}
 	c.User = "gromit"
 	c.Password = "penguin"
-	c.Timeout = 1.2345
 	c.tlsConfig = &tls.Config{}
-	c.TransactionIsolation = transactionIsolation

 	uri := c.GetDBUri("test")
-	test.S(t).ExpectEquals(uri, `gromit:penguin@tcp(myhost:3306)/test?autocommit=true&charset=utf8mb4,utf8,latin1&interpolateParams=true&tls=ghost&transaction_isolation="REPEATABLE-READ"&timeout=1.234500s&readTimeout=1.234500s&writeTimeout=1.234500s`)
+	test.S(t).ExpectEquals(uri, "gromit:penguin@tcp(myhost:3306)/test?timeout=0.000000s&readTimeout=0.000000s&writeTimeout=0.000000s&interpolateParams=true&autocommit=true&charset=utf8mb4,utf8,latin1&tls=ghost")
 }
--- a/go/mysql/instance_key.go
+++ b/go/mysql/instance_key.go
@ -1,6 +1,5 @@
 /*
   Copyright 2015 Shlomi Noach, courtesy Booking.com
-   Copyright 2022 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -13,16 +12,15 @@ import (
 	"strings"
 )

-const DefaultInstancePort = 3306
+const (
+	DefaultInstancePort = 3306
+)

 var (
 	ipv4HostPortRegexp = regexp.MustCompile("^([^:]+):([0-9]+)$")
 	ipv4HostRegexp     = regexp.MustCompile("^([^:]+)$")
-
-	// e.g. [2001:db8:1f70::999:de8:7648:6e8]:3308
-	ipv6HostPortRegexp = regexp.MustCompile("^\\[([:0-9a-fA-F]+)\\]:([0-9]+)$") //nolint:gosimple
-	// e.g. 2001:db8:1f70::999:de8:7648:6e8
-	ipv6HostRegexp = regexp.MustCompile("^([:0-9a-fA-F]+)$")
+	ipv6HostPortRegexp = regexp.MustCompile("^\\[([:0-9a-fA-F]+)\\]:([0-9]+)$") // e.g. [2001:db8:1f70::999:de8:7648:6e8]:3308
+	ipv6HostRegexp     = regexp.MustCompile("^([:0-9a-fA-F]+)$")                // e.g. 2001:db8:1f70::999:de8:7648:6e8
 )

 // InstanceKey is an instance indicator, identified by hostname and port
@ -35,7 +33,8 @@ const detachHint = "//"

 // ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306
 func NewRawInstanceKey(hostPort string) (*InstanceKey, error) {
-	var hostname, port string
+	hostname := ""
+	port := ""
 	if submatch := ipv4HostPortRegexp.FindStringSubmatch(hostPort); len(submatch) > 0 {
 		hostname = submatch[1]
 		port = submatch[2]
--- a/go/mysql/instance_key_test.go
+++ b/go/mysql/instance_key_test.go
@ -8,8 +8,8 @@ package mysql
 import (
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
--- a/go/mysql/utils.go
+++ b/go/mysql/utils.go
@ -14,15 +14,12 @@ import (

 	"github.com/github/gh-ost/go/sql"

-	"github.com/openark/golib/log"
-	"github.com/openark/golib/sqlutils"
+	"github.com/outbrain/golib/log"
+	"github.com/outbrain/golib/sqlutils"
 )

-const (
-	MaxTableNameLength           = 64
-	MaxReplicationPasswordLength = 32
-	MaxDBPoolConnections         = 3
-)
+const MaxTableNameLength = 64
+const MaxReplicationPasswordLength = 32

 type ReplicationLagResult struct {
 	Key InstanceKey
@ -42,22 +39,23 @@ func (this *ReplicationLagResult) HasLag() bool {
 var knownDBs map[string]*gosql.DB = make(map[string]*gosql.DB)
 var knownDBsMutex = &sync.Mutex{}

-func GetDB(migrationUuid string, mysql_uri string) (db *gosql.DB, exists bool, err error) {
+func GetDB(migrationUuid string, mysql_uri string) (*gosql.DB, bool, error) {
 	cacheKey := migrationUuid + ":" + mysql_uri

 	knownDBsMutex.Lock()
-	defer knownDBsMutex.Unlock()
+	defer func() {
+		knownDBsMutex.Unlock()
+	}()

-	if db, exists = knownDBs[cacheKey]; !exists {
-		db, err = gosql.Open("mysql", mysql_uri)
-		if err != nil {
-			return nil, false, err
+	var exists bool
+	if _, exists = knownDBs[cacheKey]; !exists {
+		if db, err := gosql.Open("mysql", mysql_uri); err == nil {
+			knownDBs[cacheKey] = db
+		} else {
+			return db, exists, err
 		}
-		db.SetMaxOpenConns(MaxDBPoolConnections)
-		db.SetMaxIdleConns(MaxDBPoolConnections)
-		knownDBs[cacheKey] = db
 	}
-	return db, exists, nil
+	return knownDBs[cacheKey], exists, nil
 }

 // GetReplicationLagFromSlaveStatus returns replication lag for a given db; via SHOW SLAVE STATUS
@ -205,9 +203,3 @@ func GetTableColumns(db *gosql.DB, databaseName, tableName string) (*sql.ColumnL
 	}
 	return sql.NewColumnList(columnNames), sql.NewColumnList(virtualColumnNames), nil
 }
-
-// Kill executes a KILL QUERY by connection id
-func Kill(db *gosql.DB, connectionID string) error {
-	_, err := db.Exec(`KILL QUERY %s`, connectionID)
-	return err
-}
--- a/go/os/process.go
+++ b/go/os/process.go
@ -0,0 +1,65 @@
+/*
+   Copyright 2014 Outbrain Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package os
+
+import (
+	"github.com/outbrain/golib/log"
+	"io/ioutil"
+	"os"
+	"os/exec"
+)
+
+func execCmd(commandText string, arguments ...string) (*exec.Cmd, string, error) {
+	commandBytes := []byte(commandText)
+	tmpFile, err := ioutil.TempFile("", "gh-ost-process-cmd-")
+	if err != nil {
+		return nil, "", log.Errore(err)
+	}
+	ioutil.WriteFile(tmpFile.Name(), commandBytes, 0644)
+	log.Debugf("execCmd: %s", commandText)
+	shellArguments := append([]string{}, tmpFile.Name())
+	shellArguments = append(shellArguments, arguments...)
+	log.Debugf("%+v", shellArguments)
+	return exec.Command("bash", shellArguments...), tmpFile.Name(), nil
+}
+
+// CommandRun executes a command
+func CommandRun(commandText string, arguments ...string) error {
+	cmd, tmpFileName, err := execCmd(commandText, arguments...)
+	defer os.Remove(tmpFileName)
+	if err != nil {
+		return log.Errore(err)
+	}
+	err = cmd.Run()
+	return log.Errore(err)
+}
+
+// RunCommandWithOutput executes a command and return output bytes
+func RunCommandWithOutput(commandText string) ([]byte, error) {
+	cmd, tmpFileName, err := execCmd(commandText)
+	defer os.Remove(tmpFileName)
+	if err != nil {
+		return nil, log.Errore(err)
+	}
+
+	outputBytes, err := cmd.Output()
+	if err != nil {
+		return nil, log.Errore(err)
+	}
+
+	return outputBytes, nil
+}
--- a/go/sql/builder.go
+++ b/go/sql/builder.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -33,13 +33,11 @@ func EscapeName(name string) string {
 }

 func buildColumnsPreparedValues(columns *ColumnList) []string {
-	values := make([]string, columns.Len())
+	values := make([]string, columns.Len(), columns.Len())
 	for i, column := range columns.Columns() {
 		var token string
 		if column.timezoneConversion != nil {
 			token = fmt.Sprintf("convert_tz(?, '%s', '%s')", column.timezoneConversion.ToTimezone, "+00:00")
-		} else if column.enumToTextConversion {
-			token = fmt.Sprintf("ELT(?, %s)", column.EnumValues)
 		} else if column.Type == JSONColumnType {
 			token = "convert(? using utf8mb4)"
 		} else {
@ -51,7 +49,7 @@ func buildColumnsPreparedValues(columns *ColumnList) []string {
 }

 func buildPreparedValues(length int) []string {
-	values := make([]string, length)
+	values := make([]string, length, length)
 	for i := 0; i < length; i++ {
 		values[i] = "?"
 	}
@ -59,7 +57,7 @@ func buildPreparedValues(length int) []string {
 }

 func duplicateNames(names []string) []string {
-	duplicate := make([]string, len(names))
+	duplicate := make([]string, len(names), len(names))
 	copy(duplicate, names)
 	return duplicate
 }
@ -110,8 +108,6 @@ func BuildSetPreparedClause(columns *ColumnList) (result string, err error) {
 		var setToken string
 		if column.timezoneConversion != nil {
 			setToken = fmt.Sprintf("%s=convert_tz(?, '%s', '%s')", EscapeName(column.Name), column.timezoneConversion.ToTimezone, "+00:00")
-		} else if column.enumToTextConversion {
-			setToken = fmt.Sprintf("%s=ELT(?, %s)", EscapeName(column.Name), column.EnumValues)
 		} else if column.Type == JSONColumnType {
 			setToken = fmt.Sprintf("%s=convert(? using utf8mb4)", EscapeName(column.Name))
 		} else {
@ -167,7 +163,7 @@ func BuildRangeComparison(columns []string, values []string, args []interface{},
 	if includeEquals {
 		comparison, err := BuildEqualsComparison(columns, values)
 		if err != nil {
-			return "", explodedArgs, err
+			return "", explodedArgs, nil
 		}
 		comparisons = append(comparisons, comparison)
 		explodedArgs = append(explodedArgs, args...)
@ -261,8 +257,8 @@ func BuildUniqueKeyRangeEndPreparedQueryViaOffset(databaseName, tableName string
 	explodedArgs = append(explodedArgs, rangeExplodedArgs...)

 	uniqueKeyColumnNames := duplicateNames(uniqueKeyColumns.Names())
-	uniqueKeyColumnAscending := make([]string, len(uniqueKeyColumnNames))
-	uniqueKeyColumnDescending := make([]string, len(uniqueKeyColumnNames))
+	uniqueKeyColumnAscending := make([]string, len(uniqueKeyColumnNames), len(uniqueKeyColumnNames))
+	uniqueKeyColumnDescending := make([]string, len(uniqueKeyColumnNames), len(uniqueKeyColumnNames))
 	for i, column := range uniqueKeyColumns.Columns() {
 		uniqueKeyColumnNames[i] = EscapeName(uniqueKeyColumnNames[i])
 		if column.Type == EnumColumnType {
@ -316,8 +312,8 @@ func BuildUniqueKeyRangeEndPreparedQueryViaTemptable(databaseName, tableName str
 	explodedArgs = append(explodedArgs, rangeExplodedArgs...)

 	uniqueKeyColumnNames := duplicateNames(uniqueKeyColumns.Names())
-	uniqueKeyColumnAscending := make([]string, len(uniqueKeyColumnNames))
-	uniqueKeyColumnDescending := make([]string, len(uniqueKeyColumnNames))
+	uniqueKeyColumnAscending := make([]string, len(uniqueKeyColumnNames), len(uniqueKeyColumnNames))
+	uniqueKeyColumnDescending := make([]string, len(uniqueKeyColumnNames), len(uniqueKeyColumnNames))
 	for i, column := range uniqueKeyColumns.Columns() {
 		uniqueKeyColumnNames[i] = EscapeName(uniqueKeyColumnNames[i])
 		if column.Type == EnumColumnType {
@ -368,7 +364,7 @@ func buildUniqueKeyMinMaxValuesPreparedQuery(databaseName, tableName string, uni
 	tableName = EscapeName(tableName)

 	uniqueKeyColumnNames := duplicateNames(uniqueKeyColumns.Names())
-	uniqueKeyColumnOrder := make([]string, len(uniqueKeyColumnNames))
+	uniqueKeyColumnOrder := make([]string, len(uniqueKeyColumnNames), len(uniqueKeyColumnNames))
 	for i, column := range uniqueKeyColumns.Columns() {
 		uniqueKeyColumnNames[i] = EscapeName(uniqueKeyColumnNames[i])
 		if column.Type == EnumColumnType {
@ -400,7 +396,7 @@ func BuildDMLDeleteQuery(databaseName, tableName string, tableColumns, uniqueKey
 	}
 	for _, column := range uniqueKeyColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(args[tableOrdinal], true)
+		arg := column.convertArg(args[tableOrdinal])
 		uniqueKeyArgs = append(uniqueKeyArgs, arg)
 	}
 	databaseName = EscapeName(databaseName)
@ -437,7 +433,7 @@ func BuildDMLInsertQuery(databaseName, tableName string, tableColumns, sharedCol

 	for _, column := range sharedColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(args[tableOrdinal], false)
+		arg := column.convertArg(args[tableOrdinal])
 		sharedArgs = append(sharedArgs, arg)
 	}

@ -485,13 +481,13 @@ func BuildDMLUpdateQuery(databaseName, tableName string, tableColumns, sharedCol

 	for _, column := range sharedColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(valueArgs[tableOrdinal], false)
+		arg := column.convertArg(valueArgs[tableOrdinal])
 		sharedArgs = append(sharedArgs, arg)
 	}

 	for _, column := range uniqueKeyColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(whereArgs[tableOrdinal], true)
+		arg := column.convertArg(whereArgs[tableOrdinal])
 		uniqueKeyArgs = append(uniqueKeyArgs, arg)
 	}

@ -501,17 +497,14 @@ func BuildDMLUpdateQuery(databaseName, tableName string, tableColumns, sharedCol
 	}

 	equalsComparison, err := BuildEqualsPreparedComparison(uniqueKeyColumns.Names())
-	if err != nil {
-		return "", sharedArgs, uniqueKeyArgs, err
-	}
 	result = fmt.Sprintf(`
-			update /* gh-ost %s.%s */
-					%s.%s
+ 			update /* gh-ost %s.%s */
+ 					%s.%s
 				set
 					%s
 				where
-					%s
-		`, databaseName, tableName,
+ 					%s
+ 		`, databaseName, tableName,
 		databaseName, tableName,
 		setClause,
 		equalsComparison,
--- a/go/sql/builder_test.go
+++ b/go/sql/builder_test.go
@ -12,8 +12,8 @@ import (
 	"regexp"
 	"strings"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 var (
--- a/go/sql/parser.go
+++ b/go/sql/parser.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -16,7 +16,6 @@ var (
 	renameColumnRegexp                   = regexp.MustCompile(`(?i)\bchange\s+(column\s+|)([\S]+)\s+([\S]+)\s+`)
 	dropColumnRegexp                     = regexp.MustCompile(`(?i)\bdrop\s+(column\s+|)([\S]+)$`)
 	renameTableRegexp                    = regexp.MustCompile(`(?i)\brename\s+(to|as)\s+`)
-	autoIncrementRegexp                  = regexp.MustCompile(`(?i)\bauto_increment[\s]*=[\s]*([0-9]+)`)
 	alterTableExplicitSchemaTableRegexps = []*regexp.Regexp{
 		// ALTER TABLE `scm`.`tbl` something
 		regexp.MustCompile(`(?i)\balter\s+table\s+` + "`" + `([^` + "`" + `]+)` + "`" + `[.]` + "`" + `([^` + "`" + `]+)` + "`" + `\s+(.*$)`),
@ -33,14 +32,12 @@ var (
 		// ALTER TABLE tbl something
 		regexp.MustCompile(`(?i)\balter\s+table\s+([\S]+)\s+(.*$)`),
 	}
-	enumValuesRegexp = regexp.MustCompile("^enum[(](.*)[)]$")
 )

 type AlterTableParser struct {
-	columnRenameMap        map[string]string
-	droppedColumns         map[string]bool
-	isRenameTable          bool
-	isAutoIncrementDefined bool
+	columnRenameMap map[string]string
+	droppedColumns  map[string]bool
+	isRenameTable   bool

 	alterStatementOptions string
 	alterTokens           []string
@ -62,7 +59,7 @@ func NewParserFromAlterStatement(alterStatement string) *AlterTableParser {
 	return parser
 }

-func (this *AlterTableParser) tokenizeAlterStatement(alterStatement string) (tokens []string) {
+func (this *AlterTableParser) tokenizeAlterStatement(alterStatement string) (tokens []string, err error) {
 	terminatingQuote := rune(0)
 	f := func(c rune) bool {
 		switch {
@ -86,7 +83,7 @@ func (this *AlterTableParser) tokenizeAlterStatement(alterStatement string) (tok
 	for i := range tokens {
 		tokens[i] = strings.TrimSpace(tokens[i])
 	}
-	return tokens
+	return tokens, nil
 }

 func (this *AlterTableParser) sanitizeQuotesFromAlterStatement(alterStatement string) (strippedStatement string) {
@ -95,7 +92,7 @@ func (this *AlterTableParser) sanitizeQuotesFromAlterStatement(alterStatement st
 	return strippedStatement
 }

-func (this *AlterTableParser) parseAlterToken(alterToken string) {
+func (this *AlterTableParser) parseAlterToken(alterToken string) (err error) {
 	{
 		// rename
 		allStringSubmatch := renameColumnRegexp.FindAllStringSubmatch(alterToken, -1)
@ -125,15 +122,11 @@ func (this *AlterTableParser) parseAlterToken(alterToken string) {
 			this.isRenameTable = true
 		}
 	}
-	{
-		// auto_increment
-		if autoIncrementRegexp.MatchString(alterToken) {
-			this.isAutoIncrementDefined = true
-		}
-	}
+	return nil
 }

 func (this *AlterTableParser) ParseAlterStatement(alterStatement string) (err error) {
+
 	this.alterStatementOptions = alterStatement
 	for _, alterTableRegexp := range alterTableExplicitSchemaTableRegexps {
 		if submatch := alterTableRegexp.FindStringSubmatch(this.alterStatementOptions); len(submatch) > 0 {
@ -150,7 +143,8 @@ func (this *AlterTableParser) ParseAlterStatement(alterStatement string) (err er
 			break
 		}
 	}
-	for _, alterToken := range this.tokenizeAlterStatement(this.alterStatementOptions) {
+	alterTokens, _ := this.tokenizeAlterStatement(this.alterStatementOptions)
+	for _, alterToken := range alterTokens {
 		alterToken = this.sanitizeQuotesFromAlterStatement(alterToken)
 		this.parseAlterToken(alterToken)
 		this.alterTokens = append(this.alterTokens, alterToken)
@ -179,11 +173,6 @@ func (this *AlterTableParser) DroppedColumnsMap() map[string]bool {
 func (this *AlterTableParser) IsRenameTable() bool {
 	return this.isRenameTable
 }
-
-func (this *AlterTableParser) IsAutoIncrementDefined() bool {
-	return this.isAutoIncrementDefined
-}
-
 func (this *AlterTableParser) GetExplicitSchema() string {
 	return this.explicitSchema
 }
@ -203,10 +192,3 @@ func (this *AlterTableParser) HasExplicitTable() bool {
 func (this *AlterTableParser) GetAlterStatementOptions() string {
 	return this.alterStatementOptions
 }
-
-func ParseEnumValues(enumColumnType string) string {
-	if submatch := enumValuesRegexp.FindStringSubmatch(enumColumnType); len(submatch) > 0 {
-		return submatch[1]
-	}
-	return enumColumnType
-}
--- a/go/sql/parser_test.go
+++ b/go/sql/parser_test.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2022 GitHub Inc.
+   Copyright 2016 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -9,8 +9,8 @@ import (
 	"reflect"
 	"testing"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
@ -24,7 +24,6 @@ func TestParseAlterStatement(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
-	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 }

 func TestParseAlterStatementTrivialRename(t *testing.T) {
@ -34,30 +33,10 @@ func TestParseAlterStatementTrivialRename(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
-	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 	test.S(t).ExpectEquals(len(parser.columnRenameMap), 1)
 	test.S(t).ExpectEquals(parser.columnRenameMap["ts"], "ts")
 }

-func TestParseAlterStatementWithAutoIncrement(t *testing.T) {
-	statements := []string{
-		"auto_increment=7",
-		"auto_increment = 7",
-		"AUTO_INCREMENT = 71",
-		"add column t int, change ts ts timestamp, auto_increment=7 engine=innodb",
-		"add column t int, change ts ts timestamp, auto_increment =7 engine=innodb",
-		"add column t int, change ts ts timestamp, AUTO_INCREMENT = 7 engine=innodb",
-		"add column t int, change ts ts timestamp, engine=innodb auto_increment=73425",
-	}
-	for _, statement := range statements {
-		parser := NewAlterTableParser()
-		err := parser.ParseAlterStatement(statement)
-		test.S(t).ExpectNil(err)
-		test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
-		test.S(t).ExpectTrue(parser.IsAutoIncrementDefined())
-	}
-}
-
 func TestParseAlterStatementTrivialRenames(t *testing.T) {
 	statement := "add column t int, change ts ts timestamp, CHANGE f `f` float, engine=innodb"
 	parser := NewAlterTableParser()
@ -65,7 +44,6 @@ func TestParseAlterStatementTrivialRenames(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
-	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 	test.S(t).ExpectEquals(len(parser.columnRenameMap), 2)
 	test.S(t).ExpectEquals(parser.columnRenameMap["ts"], "ts")
 	test.S(t).ExpectEquals(parser.columnRenameMap["f"], "f")
@ -86,7 +64,6 @@ func TestParseAlterStatementNonTrivial(t *testing.T) {
 		parser := NewAlterTableParser()
 		err := parser.ParseAlterStatement(statement)
 		test.S(t).ExpectNil(err)
-		test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 		test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 		renames := parser.GetNonTrivialRenames()
 		test.S(t).ExpectEquals(len(renames), 2)
@ -99,37 +76,37 @@ func TestTokenizeAlterStatement(t *testing.T) {
 	parser := NewAlterTableParser()
 	{
 		alterStatement := "add column t int"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int"}))
 	}
 	{
 		alterStatement := "add column t int, change column i int"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int", "change column i int"}))
 	}
 	{
 		alterStatement := "add column t int, change column i int 'some comment'"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int", "change column i int 'some comment'"}))
 	}
 	{
 		alterStatement := "add column t int, change column i int 'some comment, with comma'"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int", "change column i int 'some comment, with comma'"}))
 	}
 	{
 		alterStatement := "add column t int, add column d decimal(10,2)"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int", "add column d decimal(10,2)"}))
 	}
 	{
 		alterStatement := "add column t int, add column e enum('a','b','c')"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int", "add column e enum('a','b','c')"}))
 	}
 	{
 		alterStatement := "add column t int(11), add column e enum('a','b','c')"
-		tokens := parser.tokenizeAlterStatement(alterStatement)
+		tokens, _ := parser.tokenizeAlterStatement(alterStatement)
 		test.S(t).ExpectTrue(reflect.DeepEqual(tokens, []string{"add column t int(11)", "add column e enum('a','b','c')"}))
 	}
 }
@ -149,6 +126,7 @@ func TestSanitizeQuotesFromAlterStatement(t *testing.T) {
 }

 func TestParseAlterStatementDroppedColumns(t *testing.T) {
+
 	{
 		parser := NewAlterTableParser()
 		statement := "drop column b"
@ -188,6 +166,7 @@ func TestParseAlterStatementDroppedColumns(t *testing.T) {
 }

 func TestParseAlterStatementRenameTable(t *testing.T) {
+
 	{
 		parser := NewAlterTableParser()
 		statement := "drop column b"
@ -227,6 +206,7 @@ func TestParseAlterStatementRenameTable(t *testing.T) {
 }

 func TestParseAlterStatementExplicitTable(t *testing.T) {
+
 	{
 		parser := NewAlterTableParser()
 		statement := "drop column b"
@ -318,21 +298,3 @@ func TestParseAlterStatementExplicitTable(t *testing.T) {
 		test.S(t).ExpectTrue(reflect.DeepEqual(parser.alterTokens, []string{"drop column b", "add index idx(i)"}))
 	}
 }
-
-func TestParseEnumValues(t *testing.T) {
-	{
-		s := "enum('red','green','blue','orange')"
-		values := ParseEnumValues(s)
-		test.S(t).ExpectEquals(values, "'red','green','blue','orange'")
-	}
-	{
-		s := "('red','green','blue','orange')"
-		values := ParseEnumValues(s)
-		test.S(t).ExpectEquals(values, "('red','green','blue','orange')")
-	}
-	{
-		s := "zzz"
-		values := ParseEnumValues(s)
-		test.S(t).ExpectEquals(values, "zzz")
-	}
-}
--- a/go/sql/types.go
+++ b/go/sql/types.go
@ -6,7 +6,6 @@
 package sql

 import (
-	"bytes"
 	"fmt"
 	"reflect"
 	"strconv"
@ -23,7 +22,6 @@ const (
 	MediumIntColumnType
 	JSONColumnType
 	FloatColumnType
-	BinaryColumnType
 )

 const maxMediumintUnsigned int32 = 16777215
@ -32,48 +30,20 @@ type TimezoneConversion struct {
 	ToTimezone string
 }

-type CharacterSetConversion struct {
-	ToCharset   string
-	FromCharset string
-}
-
 type Column struct {
-	Name                 string
-	IsUnsigned           bool
-	Charset              string
-	Type                 ColumnType
-	EnumValues           string
-	timezoneConversion   *TimezoneConversion
-	enumToTextConversion bool
-	// add Octet length for binary type, fix bytes with suffix "00" get clipped in mysql binlog.
-	// https://github.com/github/gh-ost/issues/909
-	BinaryOctetLength uint
-	charsetConversion *CharacterSetConversion
+	Name               string
+	IsUnsigned         bool
+	Charset            string
+	Type               ColumnType
+	timezoneConversion *TimezoneConversion
 }

-func (this *Column) convertArg(arg interface{}, isUniqueKeyColumn bool) interface{} {
+func (this *Column) convertArg(arg interface{}) interface{} {
 	if s, ok := arg.(string); ok {
-		arg2Bytes := []byte(s)
-		// convert to bytes if character string without charsetConversion.
-		if this.Charset != "" && this.charsetConversion == nil {
-			arg = arg2Bytes
-		} else {
-			if encoding, ok := charsetEncodingMap[this.Charset]; ok {
-				arg, _ = encoding.NewDecoder().String(s)
-			}
+		// string, charset conversion
+		if encoding, ok := charsetEncodingMap[this.Charset]; ok {
+			arg, _ = encoding.NewDecoder().String(s)
 		}
-
-		if this.Type == BinaryColumnType && isUniqueKeyColumn {
-			size := len(arg2Bytes)
-			if uint(size) < this.BinaryOctetLength {
-				buf := bytes.NewBuffer(arg2Bytes)
-				for i := uint(0); i < (this.BinaryOctetLength - uint(size)); i++ {
-					buf.Write([]byte{0})
-				}
-				arg = buf.String()
-			}
-		}
-
 		return arg
 	}

@ -209,18 +179,6 @@ func (this *ColumnList) HasTimezoneConversion(columnName string) bool {
 	return this.GetColumn(columnName).timezoneConversion != nil
 }

-func (this *ColumnList) SetEnumToTextConversion(columnName string) {
-	this.GetColumn(columnName).enumToTextConversion = true
-}
-
-func (this *ColumnList) IsEnumToTextConversion(columnName string) bool {
-	return this.GetColumn(columnName).enumToTextConversion
-}
-
-func (this *ColumnList) SetEnumValues(columnName string, enumValues string) {
-	this.GetColumn(columnName).EnumValues = enumValues
-}
-
 func (this *ColumnList) String() string {
 	return strings.Join(this.Names(), ",")
 }
@ -248,10 +206,6 @@ func (this *ColumnList) Len() int {
 	return len(this.columns)
 }

-func (this *ColumnList) SetCharsetConversion(columnName string, fromCharset string, toCharset string) {
-	this.GetColumn(columnName).charsetConversion = &CharacterSetConversion{FromCharset: fromCharset, ToCharset: toCharset}
-}
-
 // UniqueKey is the combination of a key's name and columns
 type UniqueKey struct {
 	Name            string
--- a/go/sql/types_test.go
+++ b/go/sql/types_test.go
@ -10,8 +10,8 @@ import (

 	"reflect"

-	"github.com/openark/golib/log"
-	test "github.com/openark/golib/tests"
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
 )

 func init() {
--- a/localtests/attempt-instant-ddl/create.sql
+++ b/localtests/attempt-instant-ddl/create.sql
@ -1,13 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  color varchar(32),
-  primary key(id)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-
-insert into gh_ost_test values (null, 11, 'red');
-insert into gh_ost_test values (null, 13, 'green');
-insert into gh_ost_test values (null, 17, 'blue');
--- a/localtests/attempt-instant-ddl/extra_args
+++ b/localtests/attempt-instant-ddl/extra_args
@ -1 +0,0 @@
--attempt-instant-ddl
--- a/localtests/autoinc-copy-deletes-user-defined/create.sql
+++ b/localtests/autoinc-copy-deletes-user-defined/create.sql
@ -1,17 +0,0 @@
-drop event if exists gh_ost_test;
-
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  primary key(id)
-) auto_increment=1;
-
-insert into gh_ost_test values (NULL, 11);
-insert into gh_ost_test values (NULL, 13);
-insert into gh_ost_test values (NULL, 17);
-insert into gh_ost_test values (NULL, 23);
-insert into gh_ost_test values (NULL, 29);
-insert into gh_ost_test values (NULL, 31);
-insert into gh_ost_test values (NULL, 37);
-delete from gh_ost_test where id>=5;
--- a/localtests/autoinc-copy-deletes-user-defined/expect_table_structure
+++ b/localtests/autoinc-copy-deletes-user-defined/expect_table_structure
@ -1 +0,0 @@
-AUTO_INCREMENT=7
--- a/localtests/autoinc-copy-deletes-user-defined/extra_args
+++ b/localtests/autoinc-copy-deletes-user-defined/extra_args
@ -1 +0,0 @@
--alter='AUTO_INCREMENT=7'
--- a/localtests/autoinc-copy-deletes/create.sql
+++ b/localtests/autoinc-copy-deletes/create.sql
@ -1,17 +0,0 @@
-drop event if exists gh_ost_test;
-
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  primary key(id)
-) auto_increment=1;
-
-insert into gh_ost_test values (NULL, 11);
-insert into gh_ost_test values (NULL, 13);
-insert into gh_ost_test values (NULL, 17);
-insert into gh_ost_test values (NULL, 23);
-insert into gh_ost_test values (NULL, 29);
-insert into gh_ost_test values (NULL, 31);
-insert into gh_ost_test values (NULL, 37);
-delete from gh_ost_test where id>=5;
--- a/localtests/autoinc-copy-deletes/expect_table_structure
+++ b/localtests/autoinc-copy-deletes/expect_table_structure
@ -1 +0,0 @@
-AUTO_INCREMENT=8
--- a/localtests/autoinc-copy-simple/create.sql
+++ b/localtests/autoinc-copy-simple/create.sql
@ -1,13 +0,0 @@
-drop event if exists gh_ost_test;
-
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  primary key(id)
-) auto_increment=1;
-
-insert into gh_ost_test values (NULL, 11);
-insert into gh_ost_test values (NULL, 13);
-insert into gh_ost_test values (NULL, 17);
-insert into gh_ost_test values (NULL, 23);
--- a/localtests/autoinc-copy-simple/expect_table_structure
+++ b/localtests/autoinc-copy-simple/expect_table_structure
@ -1 +0,0 @@
-AUTO_INCREMENT=5
--- a/localtests/compound-pk-ts/create.sql
+++ b/localtests/compound-pk-ts/create.sql
@ -1,40 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  ts0 timestamp(6) default current_timestamp(6),
-  updated tinyint unsigned default 0,
-  primary key(id, ts0)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 11, sysdate(6), 0);
-  update gh_ost_test set updated = 1 where i = 11 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 13,  sysdate(6), 0);
-  update gh_ost_test set updated = 1 where i = 13 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 17, sysdate(6), 0);
-  update gh_ost_test set updated = 1 where i = 17 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 19, sysdate(6), 0);
-  update gh_ost_test set updated = 1 where i = 19 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 23, sysdate(6), 0);
-  update gh_ost_test set updated = 1 where i = 23 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 29, sysdate(6), 0);
-  insert into gh_ost_test values (null, 31, sysdate(6), 0);
-  insert into gh_ost_test values (null, 37, sysdate(6), 0);
-  insert into gh_ost_test values (null, 41, sysdate(6), 0);
-  delete from gh_ost_test where i = 31 order by id desc limit 1;
-end ;;
--- a/localtests/compound-pk/create.sql
+++ b/localtests/compound-pk/create.sql
@ -1,40 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  v varchar(128),
-  updated tinyint unsigned default 0,
-  primary key(id, v)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 11, 'eleven', 0);
-  update gh_ost_test set updated = 1 where i = 11 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 13,  'thirteen', 0);
-  update gh_ost_test set updated = 1 where i = 13 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 17, 'seventeen', 0);
-  update gh_ost_test set updated = 1 where i = 17 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 19, 'nineteen', 0);
-  update gh_ost_test set updated = 1 where i = 19 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 23, 'twenty three', 0);
-  update gh_ost_test set updated = 1 where i = 23 order by id desc limit 1;
-
-  insert into gh_ost_test values (null, 29, 'twenty nine', 0);
-  insert into gh_ost_test values (null, 31, 'thirty one', 0);
-  insert into gh_ost_test values (null, 37, 'thirty seven', 0);
-  insert into gh_ost_test values (null, 41, 'forty one', 0);
-  delete from gh_ost_test where i = 31 order by id desc limit 1;
-end ;;
--- a/localtests/convert-utf8mb4/create.sql
+++ b/localtests/convert-utf8mb4/create.sql
@ -7,6 +7,9 @@ create table gh_ost_test (
  primary key(id)
 ) auto_increment=1;

+insert into gh_ost_test values (null, 'átesting');
+
+
 insert into gh_ost_test values (null, 'Hello world, Καλημέρα κόσμε, コンニチハ', 'átesting0', 'initial');

 drop event if exists gh_ost_test;
--- a/localtests/datetime-submillis-zeroleading/ignore_versions
+++ b/localtests/datetime-submillis-zeroleading/ignore_versions
@ -0,0 +1 @@
+(5.5)
--- a/localtests/datetime-submillis/ignore_versions
+++ b/localtests/datetime-submillis/ignore_versions
@ -0,0 +1 @@
+(5.5)
--- a/localtests/datetime-to-timestamp-pk-fail/ignore_versions
+++ b/localtests/datetime-to-timestamp-pk-fail/ignore_versions
@ -0,0 +1 @@
+(5.5)
--- a/localtests/datetime-with-zero/create.sql
+++ b/localtests/datetime-with-zero/create.sql
@ -1,20 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int unsigned auto_increment,
-  i int not null,
-  dt datetime,
-  primary key(id)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 7, '2010-10-20 10:20:30');
-end ;;
--- a/localtests/datetime-with-zero/extra_args
+++ b/localtests/datetime-with-zero/extra_args
@ -1 +0,0 @@
--allow-zero-in-date --alter="change column dt dt datetime not null default '1970-00-00 00:00:00'"
--- a/localtests/datetime/ignore_versions
+++ b/localtests/datetime/ignore_versions
@ -0,0 +1 @@
+(5.5)
--- a/localtests/discard-fk/ignore_versions
+++ b/localtests/discard-fk/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/localtests/enum-to-varchar/create.sql
+++ b/localtests/enum-to-varchar/create.sql
@ -1,26 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  i int not null,
-  e enum('red', 'green', 'blue', 'orange') null default null collate 'utf8_bin',
-  primary key(id)
-) auto_increment=1;
-
-insert into gh_ost_test values (null, 7, 'red');
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 11, 'red');
-  insert into gh_ost_test values (null, 13, 'green');
-  insert into gh_ost_test values (null, 17, 'blue');
-  set @last_insert_id := last_insert_id();
-  update gh_ost_test set e='orange' where id = @last_insert_id;
-end ;;
--- a/localtests/enum-to-varchar/extra_args
+++ b/localtests/enum-to-varchar/extra_args
@ -1 +0,0 @@
--alter="change e e varchar(32) not null default ''" 
--- a/localtests/existing-datetime-with-zero/create.sql
+++ b/localtests/existing-datetime-with-zero/create.sql
@ -1,21 +0,0 @@
-set session sql_mode='';
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int unsigned auto_increment,
-  i int not null,
-  dt datetime not null default '1970-00-00 00:00:00',
-  primary key(id)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 7, '2010-10-20 10:20:30');
-end ;;
--- a/localtests/existing-datetime-with-zero/extra_args
+++ b/localtests/existing-datetime-with-zero/extra_args
@ -1 +0,0 @@
--allow-zero-in-date --alter="engine=innodb"
--- a/localtests/fail-datetime-with-zero/create.sql
+++ b/localtests/fail-datetime-with-zero/create.sql
@ -1,20 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int unsigned auto_increment,
-  i int not null,
-  dt datetime,
-  primary key(id)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 7, '2010-10-20 10:20:30');
-end ;;
--- a/localtests/fail-datetime-with-zero/expect_failure
+++ b/localtests/fail-datetime-with-zero/expect_failure
@ -1 +0,0 @@
-Invalid default value for 'dt'
--- a/localtests/fail-datetime-with-zero/extra_args
+++ b/localtests/fail-datetime-with-zero/extra_args
@ -1 +0,0 @@
--alter="change column dt dt datetime not null default '1970-00-00 00:00:00'"
--- a/localtests/fail-existing-datetime-with-zero/create.sql
+++ b/localtests/fail-existing-datetime-with-zero/create.sql
@ -1,21 +0,0 @@
-set session sql_mode='';
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int unsigned auto_increment,
-  i int not null,
-  dt datetime not null default '1970-00-00 00:00:00',
-  primary key(id)
-) auto_increment=1;
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test values (null, 7, '2010-10-20 10:20:30');
-end ;;
--- a/localtests/fail-existing-datetime-with-zero/expect_failure
+++ b/localtests/fail-existing-datetime-with-zero/expect_failure
@ -1 +0,0 @@
-Invalid default value for 'dt'
--- a/localtests/fail-existing-datetime-with-zero/extra_args
+++ b/localtests/fail-existing-datetime-with-zero/extra_args
@ -1 +0,0 @@
--alter="engine=innodb"
--- a/localtests/fail-fk-parent/ignore_versions
+++ b/localtests/fail-fk-parent/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/localtests/fail-fk/ignore_versions
+++ b/localtests/fail-fk/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/localtests/generated-columns-add/ignore_versions
+++ b/localtests/generated-columns-add/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/localtests/generated-columns-add57/create.sql
+++ b/localtests/generated-columns-add57/create.sql
--- a/localtests/generated-columns-add57/extra_args
+++ b/localtests/generated-columns-add57/extra_args
--- a/localtests/generated-columns-add57/ghost_columns
+++ b/localtests/generated-columns-add57/ghost_columns
--- a/localtests/generated-columns-add57/ignore_versions
+++ b/localtests/generated-columns-add57/ignore_versions
@ -0,0 +1 @@
+(5.5|5.6)
--- a/localtests/generated-columns-add57/order_by
+++ b/localtests/generated-columns-add57/order_by
--- a/localtests/generated-columns-add57/orig_columns
+++ b/localtests/generated-columns-add57/orig_columns
--- a/localtests/generated-columns-rename/ignore_versions
+++ b/localtests/generated-columns-rename/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/localtests/generated-columns-rename57/create.sql
+++ b/localtests/generated-columns-rename57/create.sql
--- a/localtests/generated-columns-rename57/extra_args
+++ b/localtests/generated-columns-rename57/extra_args
--- a/localtests/generated-columns-rename57/ignore_versions
+++ b/localtests/generated-columns-rename57/ignore_versions
@ -0,0 +1 @@
+(5.5|5.6)
--- a/localtests/generated-columns-unique/create.sql
+++ b/localtests/generated-columns-unique/create.sql
@ -1,30 +0,0 @@
-drop table if exists gh_ost_test;
-create table gh_ost_test (
-  id int auto_increment,
-  `idb` varchar(36) CHARACTER SET utf8mb4 GENERATED ALWAYS AS (json_unquote(json_extract(`jsonobj`,_utf8mb4'$._id'))) STORED NOT NULL,
-  `jsonobj` json NOT NULL,
-  PRIMARY KEY (`id`,`idb`)
-) auto_increment=1;
-
-insert into gh_ost_test (id, jsonobj) values (null, '{"_id":2}');
-insert into gh_ost_test (id, jsonobj) values (null, '{"_id":3}');
-
-drop event if exists gh_ost_test;
-delimiter ;;
-create event gh_ost_test
-  on schedule every 1 second
-  starts current_timestamp
-  ends current_timestamp + interval 60 second
-  on completion not preserve
-  enable
-  do
-begin
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":5}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":7}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":11}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":13}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":17}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":19}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":23}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":27}');
-end ;;
--- a/localtests/generated-columns-unique/ignore_versions
+++ b/localtests/generated-columns-unique/ignore_versions
@ -1 +0,0 @@
-Percona
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Max Wagner	597eb30010	Define alter cli flag This flag not really documented, hopefully this clears up the intent.	2020-11-13 15:24:15 -07:00
Max Wagner	a93f00ae8e	Add some hints and tips for using RDS I had a little trouble figuring out how to configure the binlog format, hopefully this will help some others.	2020-11-13 15:23:55 -07:00
 @ -1 +1 @@
 .1.2
 .1.0
				`@ -1 +0,0 @@`
				`--allow-zero-in-date --alter="change column dt dt datetime not null default '1970-00-00 00:00:00'"`
				`@ -1 +0,0 @@`
				`--alter="change e e varchar(32) not null default ''"`
				`@ -1 +0,0 @@`
				`--allow-zero-in-date --alter="engine=innodb"`
				`@ -1 +0,0 @@`
				`--alter="change column dt dt datetime not null default '1970-00-00 00:00:00'"`