Merge branch 'master' into hidden-password-cmdline

2021-06-21 05:03:01 +02:00 · 2021-06-21 05:03:01 +02:00 · 7b3d688450
parent f54078af1a aef2a69903
commit 7b3d688450
50 changed files with 698 additions and 118 deletions
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -10,10 +10,10 @@ jobs:
    steps:
    - uses: actions/checkout@v2

-    - name: Set up Go 1.14
+    - name: Set up Go 1.16
      uses: actions/setup-go@v1
      with:
-        go-version: 1.14
+        go-version: 1.16

    - name: Build
      run: script/cibuild
--- a/.github/workflows/replica-tests.yml
+++ b/.github/workflows/replica-tests.yml
@ -6,14 +6,19 @@ jobs:
  build:

    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        version: [mysql-5.5.62,mysql-5.6.43,mysql-5.7.25,mysql-8.0.16]

    steps:
    - uses: actions/checkout@v2

-    - name: Set up Go 1.14
+    - name: Set up Go 1.16
      uses: actions/setup-go@v1
      with:
-        go-version: 1.14
+        go-version: 1.16

    - name: migration tests
+      env:
+        TEST_MYSQL_VERSION: ${{ matrix.version }}
      run:  script/cibuild-gh-ost-replica-tests
--- a/Dockerfile.packaging
+++ b/Dockerfile.packaging
@ -1,6 +1,4 @@
-#
-
-FROM golang:1.14.7
+FROM golang:1.16.4

 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:1.14.7
+FROM golang:1.16.4
 LABEL maintainer="github@github.com"

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

-[![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)
+[![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)

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

@ -65,6 +65,7 @@ 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?

@ -94,7 +95,7 @@ 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 `1.14` and above. To build on your own, use either:
+`gh-ost` is a Go project; it is built with Go `1.15` 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 @@
-1.1.0
+1.1.2
--- a/build.sh
+++ b/build.sh
@ -18,15 +18,16 @@ function build {
  GOOS=$3
  GOARCH=$4

-  if ! go version | egrep -q 'go(1\.1[456])' ; then
-    echo "go version must be 1.14 or above"
+  if ! go version | egrep -q 'go(1\.1[56])' ; then
+    echo "go version must be 1.15 or above"
    exit 1
  fi

+  # TODO: remove GO111MODULE once gh-ost uses Go modules
  echo "Building ${osname} binary"
  export GOOS
  export GOARCH
-  go build -ldflags "$ldflags" -o $buildpath/$target go/cmd/gh-ost/main.go
+  GO111MODULE=off go build -ldflags "$ldflags" -o $buildpath/$target go/cmd/gh-ost/main.go

  if [ $? -ne 0 ]; then
      echo "Build failed for ${osname}"
@ -40,7 +41,7 @@ function build {
    builddir=$(setuptree)
    cp $buildpath/$target $builddir/gh-ost/usr/bin
    cd $buildpath
-    fpm -v "${RELEASE_VERSION}" --epoch 1 -f -s dir -n gh-ost -m '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 $builddir/gh-ost --prefix=/ -t rpm --rpm-rpmbuild-define "_build_id_links none" .
    fpm -v "${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
 }
--- a/doc/azure.md
+++ b/doc/azure.md
@ -0,0 +1,26 @@
+`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/command-line-flags.md
+++ b/doc/command-line-flags.md
@ -6,6 +6,10 @@ A more in-depth discussion of various `gh-ost` command line flags: implementatio

 Add this flag when executing on Aliyun RDS.

+###  azure
+
+Add this flag when executing on Azure Database for MySQL.
+
 ### allow-master-master

 See [`--assume-master-host`](#assume-master-host).
@ -177,6 +181,9 @@ 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`.
--- a/doc/hooks.md
+++ b/doc/hooks.md
@ -66,6 +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_MIGRATED_HOST`
 - `GH_OST_INSPECTED_HOST`
--- a/doc/interactive-commands.md
+++ b/doc/interactive-commands.md
@ -18,6 +18,8 @@ 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/requirements-and-limitations.md
+++ b/doc/requirements-and-limitations.md
@ -41,6 +41,7 @@ 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/go/base/context.go
+++ b/go/base/context.go
@ -52,6 +52,7 @@ const (
 const (
 	HTTPStatusOK       = 200
 	MaxEventsBatchSize = 1000
+	ETAUnknown         = math.MinInt64
 )

 var (
@ -97,6 +98,7 @@ type MigrationContext struct {
 	DiscardForeignKeys       bool
 	AliyunRDS                bool
 	GoogleCloudPlatform      bool
+	AzureMySQL               bool

 	config            ContextConfig
 	configMutex       *sync.Mutex
@ -177,8 +179,11 @@ type MigrationContext struct {
 	RenameTablesEndTime                    time.Time
 	pointOfInterestTime                    time.Time
 	pointOfInterestTimeMutex               *sync.Mutex
+	lastHeartbeatOnChangelogTime           time.Time
+	lastHeartbeatOnChangelogMutex          *sync.Mutex
 	CurrentLag                             int64
 	currentProgress                        uint64
+	etaNanoseonds                          int64
 	ThrottleHTTPStatusCode                 int64
 	controlReplicasLagResult               mysql.ReplicationLagResult
 	TotalRowsCopied                        int64
@ -203,6 +208,7 @@ type MigrationContext struct {
 	OriginalTableColumns             *sql.ColumnList
 	OriginalTableVirtualColumns      *sql.ColumnList
 	OriginalTableUniqueKeys          [](*sql.UniqueKey)
+	OriginalTableAutoIncrement       uint64
 	GhostTableColumns                *sql.ColumnList
 	GhostTableVirtualColumns         *sql.ColumnList
 	GhostTableUniqueKeys             [](*sql.UniqueKey)
@ -263,6 +269,7 @@ func NewMigrationContext() *MigrationContext {
 		MaxLagMillisecondsThrottleThreshold: 1500,
 		CutOverLockTimeoutSeconds:           3,
 		DMLBatchSize:                        10,
+		etaNanoseonds:                       ETAUnknown,
 		maxLoad:                             NewLoadMap(),
 		criticalLoad:                        NewLoadMap(),
 		throttleMutex:                       &sync.Mutex{},
@ -270,6 +277,7 @@ 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(),
@ -453,6 +461,10 @@ 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))
 }
@ -465,6 +477,22 @@ 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)
@ -492,6 +520,20 @@ 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
--- a/go/base/utils.go
+++ b/go/base/utils.go
@ -15,6 +15,7 @@ import (

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

@ -64,7 +65,7 @@ func StringContainsAll(s string, substrings ...string) bool {
 	return nonEmptyStringsFound
 }

-func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext) (string, error) {
+func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext, name string) (string, error) {
 	versionQuery := `select @@global.version`
 	var port, extraPort int
 	var version string
@ -77,7 +78,8 @@ func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig,
 	}
 	// AliyunRDS set users port to "NULL", replace it by gh-ost param
 	// GCP set users port to "NULL", replace it by gh-ost param
-	if migrationContext.AliyunRDS || migrationContext.GoogleCloudPlatform {
+	// Azure MySQL set users port to a different value by design, replace it by gh-ost para
+	if migrationContext.AliyunRDS || migrationContext.GoogleCloudPlatform || migrationContext.AzureMySQL {
 		port = connectionConfig.Key.Port
 	} else {
 		portQuery := `select @@global.port`
@ -87,7 +89,7 @@ func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig,
 	}

 	if connectionConfig.Key.Port == port || (extraPort > 0 && connectionConfig.Key.Port == extraPort) {
-		migrationContext.Log.Infof("connection validated on %+v", connectionConfig.Key)
+		migrationContext.Log.Infof("%s connection validated on %+v", name, connectionConfig.Key)
 		return version, nil
 	} else if extraPort == 0 {
 		return "", fmt.Errorf("Unexpected database port reported: %+v", port)
--- a/go/cmd/gh-ost/main.go
+++ b/go/cmd/gh-ost/main.go
@ -79,6 +79,7 @@ func main() {
 	flag.BoolVar(&migrationContext.SkipStrictMode, "skip-strict-mode", false, "explicitly tell gh-ost binlog applier not to enforce strict 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")
--- a/go/logic/applier.go
+++ b/go/logic/applier.go
@ -17,6 +17,7 @@ import (
 	"github.com/github/gh-ost/go/sql"

 	"github.com/outbrain/golib/sqlutils"
+	"sync"
 )

 const (
@ -56,6 +57,7 @@ type Applier struct {
 	singletonDB       *gosql.DB
 	migrationContext  *base.MigrationContext
 	finishedMigrating int64
+	name              string
 }

 func NewApplier(migrationContext *base.MigrationContext) *Applier {
@ -63,6 +65,7 @@ func NewApplier(migrationContext *base.MigrationContext) *Applier {
 		connectionConfig:  migrationContext.ApplierConnectionConfig,
 		migrationContext:  migrationContext,
 		finishedMigrating: 0,
+		name:              "applier",
 	}
 }

@ -77,18 +80,18 @@ func (this *Applier) InitDBConnections() (err error) {
 		return err
 	}
 	this.singletonDB.SetMaxOpenConns(1)
-	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext)
+	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name)
 	if err != nil {
 		return err
 	}
-	if _, err := base.ValidateConnection(this.singletonDB, this.connectionConfig, this.migrationContext); err != nil {
+	if _, err := base.ValidateConnection(this.singletonDB, this.connectionConfig, this.migrationContext, this.name); err != nil {
 		return err
 	}
 	this.migrationContext.ApplierMySQLVersion = version
 	if err := this.validateAndReadTimeZone(); err != nil {
 		return err
 	}
-	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform {
+	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform && !this.migrationContext.AzureMySQL {
 		if impliedKey, err := mysql.GetInstanceKey(this.db); err != nil {
 			return err
 		} else {
@ -204,6 +207,25 @@ func (this *Applier) AlterGhost() error {
 	return nil
 }

+// 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")
+	return nil
+}
+
 // CreateChangelogTable creates the changelog table on the applier host
 func (this *Applier) CreateChangelogTable() error {
 	if err := this.DropChangelogTable(); err != nil {
@ -787,7 +809,7 @@ 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
@ -865,10 +887,13 @@ func (this *Applier) AtomicCutOverMagicLock(sessionIdChan chan int64, tableLocke
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		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",
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@ -64,7 +64,9 @@ 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))
--- a/go/logic/inspect.go
+++ b/go/logic/inspect.go
@ -29,12 +29,14 @@ 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",
 	}
 }

@ -52,7 +54,7 @@ func (this *Inspector) InitDBConnections() (err error) {
 	if err := this.validateConnection(); err != nil {
 		return err
 	}
-	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform {
+	if !this.migrationContext.AliyunRDS && !this.migrationContext.GoogleCloudPlatform && !this.migrationContext.AzureMySQL {
 		if impliedKey, err := mysql.GetInstanceKey(this.db); err != nil {
 			return err
 		} else {
@ -109,6 +111,10 @@ 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
 }

@ -181,9 +187,17 @@ 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)
+		}
 	}

 	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)
 		}
@ -198,7 +212,7 @@ 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)
+	version, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name)
 	this.migrationContext.InspectorMySQLVersion = version
 	return err
 }
@ -526,7 +540,7 @@ func (this *Inspector) CountTableRows() error {

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

-	query := fmt.Sprintf(`select /* gh-ost */ count(*) as rows from %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
+	query := fmt.Sprintf(`select /* gh-ost */ count(*) as count_rows from %s.%s`, sql.EscapeName(this.migrationContext.DatabaseName), sql.EscapeName(this.migrationContext.OriginalTableName))
 	var rowsEstimate int64
 	if err := this.db.QueryRow(query).Scan(&rowsEstimate); err != nil {
 		return err
@ -553,6 +567,7 @@ 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 {
@ -579,6 +594,11 @@ 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
@ -589,6 +609,24 @@ 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) {
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@ -11,6 +11,7 @@ import (
 	"math"
 	"os"
 	"strings"
+	"sync"
 	"sync/atomic"
 	"time"

@ -206,12 +207,20 @@ func (this *Migrator) canStopStreaming() bool {
 	return atomic.LoadInt64(&this.migrationContext.CutOverCompleteFlag) != 0
 }

-// onChangelogStateEvent is called when a binlog event operation on the changelog table is intercepted.
-func (this *Migrator) onChangelogStateEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
+// onChangelogEvent is called when a binlog event operation on the changelog table is intercepted.
+func (this *Migrator) onChangelogEvent(dmlEvent *binlog.BinlogDMLEvent) (err error) {
 	// Hey, I created the changelog table, I know the type of columns it has!
-	if hint := dmlEvent.NewColumnValues.StringColumn(2); hint != "state" {
+	switch hint := dmlEvent.NewColumnValues.StringColumn(2); hint {
+	case "state":
+		return this.onChangelogStateEvent(dmlEvent)
+	case "heartbeat":
+		return this.onChangelogHeartbeatEvent(dmlEvent)
+	default:
 		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)
@ -244,6 +253,18 @@ func (this *Migrator) onChangelogStateEvent(dmlEvent *binlog.BinlogDMLEvent) (er
 	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
@ -475,6 +496,13 @@ 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
 			}
@ -606,9 +634,12 @@ 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
-		this.applier.DropAtomicCutOverSentryTableIfExists()
+		dropCutOverSentryTableOnce.Do(func() {
+			this.applier.DropAtomicCutOverSentryTableIfExists()
+		})
 	}()

 	atomic.StoreInt64(&this.migrationContext.AllEventsUpToLockProcessedInjectedFlag, 0)
@ -617,7 +648,7 @@ 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)
 		}
 	}()
@ -737,7 +768,7 @@ func (this *Migrator) initiateInspector() (err error) {
 		this.migrationContext.Log.Infof("Master found to be %+v", *this.migrationContext.ApplierConnectionConfig.ImpliedKey)
 	} else {
 		// Forced master host.
-		key, err := mysql.ParseRawInstanceKeyLoose(this.migrationContext.AssumeMasterHostname)
+		key, err := mysql.ParseInstanceKey(this.migrationContext.AssumeMasterHostname)
 		if err != nil {
 			return err
 		}
@ -908,20 +939,29 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	}

 	var etaSeconds float64 = math.MaxFloat64
-	eta := "N/A"
+	var etaDuration = time.Duration(base.ETAUnknown)
 	if progressPct >= 100.0 {
-		eta = "due"
+		etaDuration = 0
 	} 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)
+			etaDuration = time.Duration(etaSeconds) * time.Second
 		} else {
-			eta = "due"
+			etaDuration = 0
 		}
 	}
+	this.migrationContext.SetETADuration(etaDuration)
+	var eta string
+	switch etaDuration {
+	case 0:
+		eta = "due"
+	case time.Duration(base.ETAUnknown):
+		eta = "N/A"
+	default:
+		eta = base.PrettifyDurationOutput(etaDuration)
+	}

 	state := "migrating"
 	if atomic.LoadInt64(&this.migrationContext.CountingRowsFlag) > 0 && !this.migrationContext.ConcurrentCountTableRows {
@ -958,13 +998,14 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {

 	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, 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, HeartbeatLag: %.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,
 	)
@ -991,7 +1032,7 @@ func (this *Migrator) initiateStreaming() error {
 		this.migrationContext.DatabaseName,
 		this.migrationContext.GetChangelogTableName(),
 		func(dmlEvent *binlog.BinlogDMLEvent) error {
-			return this.onChangelogStateEvent(dmlEvent)
+			return this.onChangelogEvent(dmlEvent)
 		},
 	)

@ -1068,6 +1109,14 @@ 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
--- a/go/logic/server.go
+++ b/go/logic/server.go
@ -1,5 +1,5 @@
 /*
-   Copyright 2016 GitHub Inc.
+   Copyright 2021 GitHub Inc.
 	 See https://github.com/github/gh-ost/blob/master/LICENSE
 */

@ -146,7 +146,9 @@ 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
+coordinates                          # Print the currently inspected coordinates
+applier                              # Print the hostname of the applier
+inspector                            # Print the hostname of the inspector
 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, ...)
@ -177,6 +179,22 @@ 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 {
--- a/go/logic/streamer.go
+++ b/go/logic/streamer.go
@ -42,6 +42,7 @@ type EventsStreamer struct {
 	listenersMutex           *sync.Mutex
 	eventsChannel            chan *binlog.BinlogEntry
 	binlogReader             *binlog.GoMySQLReader
+	name                     string
 }

 func NewEventsStreamer(migrationContext *base.MigrationContext) *EventsStreamer {
@ -51,6 +52,7 @@ func NewEventsStreamer(migrationContext *base.MigrationContext) *EventsStreamer
 		listeners:        [](*BinlogEventListener){},
 		listenersMutex:   &sync.Mutex{},
 		eventsChannel:    make(chan *binlog.BinlogEntry, EventsChannelBufferSize),
+		name:             "streamer",
 	}
 }

@ -106,7 +108,7 @@ 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); err != nil {
+	if _, err := base.ValidateConnection(this.db, this.connectionConfig, this.migrationContext, this.name); err != nil {
 		return err
 	}
 	if err := this.readCurrentBinlogCoordinates(); err != nil {
--- a/go/logic/throttler.go
+++ b/go/logic/throttler.go
@ -188,9 +188,12 @@ func (this *Throttler) collectControlReplicasLag() {
 		dbUri := connectionConfig.GetDBUri("information_schema")

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

--- a/go/mysql/connection.go
+++ b/go/mysql/connection.go
@ -92,6 +92,7 @@ func (this *ConnectionConfig) UseTLS(caCertificatePath, clientCertificate, clien
 	}

 	this.tlsConfig = &tls.Config{
+		ServerName:         this.Key.Hostname,
 		Certificates:       certs,
 		RootCAs:            rootCertPool,
 		InsecureSkipVerify: allowInsecure,
--- a/go/mysql/instance_key.go
+++ b/go/mysql/instance_key.go
@ -7,6 +7,7 @@ package mysql

 import (
 	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
 )
@ -15,6 +16,13 @@ const (
 	DefaultInstancePort = 3306
 )

+var (
+	ipv4HostPortRegexp = regexp.MustCompile("^([^:]+):([0-9]+)$")
+	ipv4HostRegexp     = regexp.MustCompile("^([^:]+)$")
+	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
 type InstanceKey struct {
 	Hostname string
@ -25,25 +33,35 @@ const detachHint = "//"

 // ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306
 func NewRawInstanceKey(hostPort string) (*InstanceKey, error) {
-	tokens := strings.SplitN(hostPort, ":", 2)
-	if len(tokens) != 2 {
-		return nil, fmt.Errorf("Cannot parse InstanceKey from %s. Expected format is host:port", hostPort)
+	hostname := ""
+	port := ""
+	if submatch := ipv4HostPortRegexp.FindStringSubmatch(hostPort); len(submatch) > 0 {
+		hostname = submatch[1]
+		port = submatch[2]
+	} else if submatch := ipv4HostRegexp.FindStringSubmatch(hostPort); len(submatch) > 0 {
+		hostname = submatch[1]
+	} else if submatch := ipv6HostPortRegexp.FindStringSubmatch(hostPort); len(submatch) > 0 {
+		hostname = submatch[1]
+		port = submatch[2]
+	} else if submatch := ipv6HostRegexp.FindStringSubmatch(hostPort); len(submatch) > 0 {
+		hostname = submatch[1]
+	} else {
+		return nil, fmt.Errorf("Cannot parse address: %s", hostPort)
 	}
-	instanceKey := &InstanceKey{Hostname: tokens[0]}
-	var err error
-	if instanceKey.Port, err = strconv.Atoi(tokens[1]); err != nil {
-		return instanceKey, fmt.Errorf("Invalid port: %s", tokens[1])
+	instanceKey := &InstanceKey{Hostname: hostname, Port: DefaultInstancePort}
+	if port != "" {
+		var err error
+		if instanceKey.Port, err = strconv.Atoi(port); err != nil {
+			return instanceKey, fmt.Errorf("Invalid port: %s", port)
+		}
 	}

 	return instanceKey, nil
 }

-// ParseRawInstanceKeyLoose will parse an InstanceKey from a string representation such as 127.0.0.1:3306.
+// ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306.
 // The port part is optional; there will be no name resolve
-func ParseRawInstanceKeyLoose(hostPort string) (*InstanceKey, error) {
-	if !strings.Contains(hostPort, ":") {
-		return &InstanceKey{Hostname: hostPort, Port: DefaultInstancePort}, nil
-	}
+func ParseInstanceKey(hostPort string) (*InstanceKey, error) {
 	return NewRawInstanceKey(hostPort)
 }

--- a/go/mysql/instance_key_map.go
+++ b/go/mysql/instance_key_map.go
@ -92,7 +92,7 @@ func (this *InstanceKeyMap) ReadCommaDelimitedList(list string) error {
 	}
 	tokens := strings.Split(list, ",")
 	for _, token := range tokens {
-		key, err := ParseRawInstanceKeyLoose(token)
+		key, err := ParseInstanceKey(token)
 		if err != nil {
 			return err
 		}
--- a/go/mysql/instance_key_test.go
+++ b/go/mysql/instance_key_test.go
@ -0,0 +1,74 @@
+/*
+   Copyright 2016 GitHub Inc.
+	 See https://github.com/github/gh-ost/blob/master/LICENSE
+*/
+
+package mysql
+
+import (
+	"testing"
+
+	"github.com/outbrain/golib/log"
+	test "github.com/outbrain/golib/tests"
+)
+
+func init() {
+	log.SetLevel(log.ERROR)
+}
+
+func TestParseInstanceKey(t *testing.T) {
+	{
+		key, err := ParseInstanceKey("myhost:1234")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "myhost")
+		test.S(t).ExpectEquals(key.Port, 1234)
+	}
+	{
+		key, err := ParseInstanceKey("myhost")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "myhost")
+		test.S(t).ExpectEquals(key.Port, 3306)
+	}
+	{
+		key, err := ParseInstanceKey("10.0.0.3:3307")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "10.0.0.3")
+		test.S(t).ExpectEquals(key.Port, 3307)
+	}
+	{
+		key, err := ParseInstanceKey("10.0.0.3")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "10.0.0.3")
+		test.S(t).ExpectEquals(key.Port, 3306)
+	}
+	{
+		key, err := ParseInstanceKey("[2001:db8:1f70::999:de8:7648:6e8]:3308")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "2001:db8:1f70::999:de8:7648:6e8")
+		test.S(t).ExpectEquals(key.Port, 3308)
+	}
+	{
+		key, err := ParseInstanceKey("::1")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "::1")
+		test.S(t).ExpectEquals(key.Port, 3306)
+	}
+	{
+		key, err := ParseInstanceKey("0:0:0:0:0:0:0:0")
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(key.Hostname, "0:0:0:0:0:0:0:0")
+		test.S(t).ExpectEquals(key.Port, 3306)
+	}
+	{
+		_, err := ParseInstanceKey("[2001:xxxx:1f70::999:de8:7648:6e8]:3308")
+		test.S(t).ExpectNotNil(err)
+	}
+	{
+		_, err := ParseInstanceKey("10.0.0.4:")
+		test.S(t).ExpectNotNil(err)
+	}
+	{
+		_, err := ParseInstanceKey("10.0.0.4:5.6.7")
+		test.S(t).ExpectNotNil(err)
+	}
+}
--- a/go/mysql/utils.go
+++ b/go/mysql/utils.go
@ -18,8 +18,11 @@ import (
 	"github.com/outbrain/golib/sqlutils"
 )

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

 type ReplicationLagResult struct {
 	Key InstanceKey
@ -39,23 +42,22 @@ 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) (*gosql.DB, bool, error) {
+func GetDB(migrationUuid string, mysql_uri string) (db *gosql.DB, exists bool, err error) {
 	cacheKey := migrationUuid + ":" + mysql_uri

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

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

 // GetReplicationLagFromSlaveStatus returns replication lag for a given db; via SHOW SLAVE STATUS
--- a/go/sql/builder.go
+++ b/go/sql/builder.go
@ -38,6 +38,8 @@ func buildColumnsPreparedValues(columns *ColumnList) []string {
 		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 {
@ -108,6 +110,8 @@ 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 {
@ -396,7 +400,7 @@ func BuildDMLDeleteQuery(databaseName, tableName string, tableColumns, uniqueKey
 	}
 	for _, column := range uniqueKeyColumns.Columns() {
 		tableOrdinal := tableColumns.Ordinals[column.Name]
-		arg := column.convertArg(args[tableOrdinal])
+		arg := column.convertArg(args[tableOrdinal], true)
 		uniqueKeyArgs = append(uniqueKeyArgs, arg)
 	}
 	databaseName = EscapeName(databaseName)
@ -433,7 +437,7 @@ func BuildDMLInsertQuery(databaseName, tableName string, tableColumns, sharedCol

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

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

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

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

--- a/go/sql/parser.go
+++ b/go/sql/parser.go
@ -16,6 +16,7 @@ var (
 	renameColumnRegexp                   = regexp.MustCompile(`(?i)\bchange\s+(column\s+|)([\S]+)\s+([\S]+)\s+`)
 	dropColumnRegexp                     = regexp.MustCompile(`(?i)\bdrop\s+(column\s+|)([\S]+)$`)
 	renameTableRegexp                    = regexp.MustCompile(`(?i)\brename\s+(to|as)\s+`)
+	autoIncrementRegexp                  = regexp.MustCompile(`(?i)\bauto_increment[\s]*=[\s]*([0-9]+)`)
 	alterTableExplicitSchemaTableRegexps = []*regexp.Regexp{
 		// ALTER TABLE `scm`.`tbl` something
 		regexp.MustCompile(`(?i)\balter\s+table\s+` + "`" + `([^` + "`" + `]+)` + "`" + `[.]` + "`" + `([^` + "`" + `]+)` + "`" + `\s+(.*$)`),
@ -32,12 +33,14 @@ 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
+	columnRenameMap        map[string]string
+	droppedColumns         map[string]bool
+	isRenameTable          bool
+	isAutoIncrementDefined bool

 	alterStatementOptions string
 	alterTokens           []string
@ -122,6 +125,12 @@ func (this *AlterTableParser) parseAlterToken(alterToken string) (err error) {
 			this.isRenameTable = true
 		}
 	}
+	{
+		// auto_increment
+		if autoIncrementRegexp.MatchString(alterToken) {
+			this.isAutoIncrementDefined = true
+		}
+	}
 	return nil
 }

@ -173,6 +182,11 @@ 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
 }
@ -192,3 +206,10 @@ 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
@ -24,6 +24,7 @@ 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) {
@ -33,10 +34,31 @@ 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()
@ -44,6 +66,7 @@ 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")
@ -64,6 +87,7 @@ 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)
@ -298,3 +322,21 @@ 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
@ -6,6 +6,7 @@
 package sql

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

 const maxMediumintUnsigned int32 = 16777215
@ -31,19 +33,37 @@ type TimezoneConversion struct {
 }

 type Column struct {
-	Name               string
-	IsUnsigned         bool
-	Charset            string
-	Type               ColumnType
-	timezoneConversion *TimezoneConversion
+	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
 }

-func (this *Column) convertArg(arg interface{}) interface{} {
+func (this *Column) convertArg(arg interface{}, isUniqueKeyColumn bool) interface{} {
 	if s, ok := arg.(string); ok {
 		// string, charset conversion
 		if encoding, ok := charsetEncodingMap[this.Charset]; ok {
 			arg, _ = encoding.NewDecoder().String(s)
 		}
+
+		if this.Type == BinaryColumnType && isUniqueKeyColumn {
+			arg2Bytes := []byte(arg.(string))
+			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
 	}

@ -179,6 +199,18 @@ 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(), ",")
 }
--- a/localtests/autoinc-copy-deletes-user-defined/create.sql
+++ b/localtests/autoinc-copy-deletes-user-defined/create.sql
@ -0,0 +1,17 @@
+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
@ -0,0 +1 @@
+AUTO_INCREMENT=7
--- a/localtests/autoinc-copy-deletes-user-defined/extra_args
+++ b/localtests/autoinc-copy-deletes-user-defined/extra_args
@ -0,0 +1 @@
+--alter='AUTO_INCREMENT=7'
--- a/localtests/autoinc-copy-deletes/create.sql
+++ b/localtests/autoinc-copy-deletes/create.sql
@ -0,0 +1,17 @@
+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
@ -0,0 +1 @@
+AUTO_INCREMENT=8
--- a/localtests/autoinc-copy-simple/create.sql
+++ b/localtests/autoinc-copy-simple/create.sql
@ -0,0 +1,13 @@
+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
@ -0,0 +1 @@
+AUTO_INCREMENT=5
--- a/localtests/enum-to-varchar/create.sql
+++ b/localtests/enum-to-varchar/create.sql
@ -0,0 +1,26 @@
+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
@ -0,0 +1 @@
+--alter="change e e varchar(32) not null default ''" 
--- a/localtests/generated-columns57-unique/create.sql
+++ b/localtests/generated-columns57-unique/create.sql
@ -0,0 +1,30 @@
+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-columns57-unique/ignore_versions
+++ b/localtests/generated-columns57-unique/ignore_versions
@ -0,0 +1 @@
+(5.5|5.6)
--- a/localtests/test.sh
+++ b/localtests/test.sh
@ -12,6 +12,7 @@ test_logfile=/tmp/gh-ost-test.log
 default_ghost_binary=/tmp/gh-ost-test
 ghost_binary=""
 exec_command_file=/tmp/gh-ost-test.bash
+ghost_structure_output_file=/tmp/gh-ost-test.ghost.structure.sql
 orig_content_output_file=/tmp/gh-ost-test.orig.content.csv
 ghost_content_output_file=/tmp/gh-ost-test.ghost.content.csv
 throttle_flag_file=/tmp/gh-ost-test.ghost.throttle.flag
@ -204,6 +205,18 @@ test_single() {
    return 1
  fi

+  gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "show create table _gh_ost_test_gho\G" -ss > $ghost_structure_output_file
+
+  if [ -f $tests_path/$test_name/expect_table_structure ] ; then
+    expected_table_structure="$(cat $tests_path/$test_name/expect_table_structure)"
+    if ! grep -q "$expected_table_structure" $ghost_structure_output_file ; then
+      echo
+      echo "ERROR $test_name: table structure was expected to include ${expected_table_structure} but did not. cat $ghost_structure_output_file:"
+      cat $ghost_structure_output_file
+      return 1
+    fi
+  fi
+
  echo_dot
  gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "select ${orig_columns} from gh_ost_test ${order_by}" -ss > $orig_content_output_file
  gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "select ${ghost_columns} from _gh_ost_test_gho ${order_by}" -ss > $ghost_content_output_file
@ -229,7 +242,10 @@ build_binary() {
    echo "Using binary: $ghost_binary"
    return 0
  fi
-  go build -o $ghost_binary go/cmd/gh-ost/main.go
+
+  # TODO: remove GO111MODULE once gh-ost uses Go modules
+  GO111MODULE=off go build -o $ghost_binary go/cmd/gh-ost/main.go
+
  if [ $? -ne 0 ] ; then
    echo "Build failure"
    exit 1
--- a/script/build
+++ b/script/build
@ -17,4 +17,5 @@ export GOPATH="$PWD/.gopath"
 cd .gopath/src/github.com/github/gh-ost

 # We put the binaries directly into the bindir, because we have no need for shim wrappers
-go build -o "$bindir/gh-ost" -ldflags "-X main.AppVersion=${version} -X main.BuildDescribe=${describe}" ./go/cmd/gh-ost/main.go
+# TODO: remove GO111MODULE once gh-ost uses Go modules
+GO111MODULE=off go build -o "$bindir/gh-ost" -ldflags "-X main.AppVersion=${version} -X main.BuildDescribe=${describe}" ./go/cmd/gh-ost/main.go
--- a/script/build-deploy-tarball
+++ b/script/build-deploy-tarball
@ -30,8 +30,6 @@ cp ${tarball}.gz "$BUILD_ARTIFACT_DIR"/gh-ost/

 ### HACK HACK HACK HACK ###
 # blame @carlosmn, @mattr and @timvaillancourt-
-# Allow builds on buster to also be used for stretch + jessie
+# Allow builds on buster to also be used for stretch
 stretch_tarball_name=$(echo $(basename "${tarball}") | sed s/-buster-/-stretch-/)
-jessie_tarball_name=$(echo $(basename "${stretch_tarball_name}") | sed s/-stretch-/-jessie-/)
 cp ${tarball}.gz "$BUILD_ARTIFACT_DIR/gh-ost/${stretch_tarball_name}.gz"
-cp ${tarball}.gz "$BUILD_ARTIFACT_DIR/gh-ost/${jessie_tarball_name}.gz"
--- a/script/cibuild-gh-ost-replica-tests
+++ b/script/cibuild-gh-ost-replica-tests
@ -4,19 +4,25 @@ set -e

 whoami

-# Clone gh-ost-ci-env
-# Only clone if not already running locally at latest commit
-remote_commit=$(git ls-remote https://github.com/github/gh-ost-ci-env.git HEAD | cut -f1)
-local_commit="unknown"
-[ -d "gh-ost-ci-env" ] && local_commit=$(cd gh-ost-ci-env && git log --format="%H" -n 1)
+fetch_ci_env() {
+  # Clone gh-ost-ci-env
+  # Only clone if not already running locally at latest commit
+  remote_commit=$(git ls-remote https://github.com/github/gh-ost-ci-env.git HEAD | cut -f1)
+  local_commit="unknown"
+  [ -d "gh-ost-ci-env" ] && local_commit=$(cd gh-ost-ci-env && git log --format="%H" -n 1)

-echo "remote commit is: $remote_commit"
-echo "local commit is:  $local_commit"
+  echo "remote commit is: $remote_commit"
+  echo "local commit is:  $local_commit"

-if [ "$remote_commit" != "$local_commit" ] ; then
-  rm -rf ./gh-ost-ci-env
-  git clone https://github.com/github/gh-ost-ci-env.git
-fi
+  if [ "$remote_commit" != "$local_commit" ] ; then
+    rm -rf ./gh-ost-ci-env
+    git clone https://github.com/github/gh-ost-ci-env.git
+  fi
+}
+
+test_dbdeployer() {
+  gh-ost-ci-env/bin/linux/dbdeployer --version
+}

 test_mysql_version() {
  local mysql_version
@ -30,17 +36,18 @@ test_mysql_version() {

  mkdir -p sandbox/binary
  rm -rf sandbox/binary/*
-  gh-ost-ci-env/bin/linux/dbdeployer unpack gh-ost-ci-env/mysql-tarballs/"$mysql_version".tar.gz --unpack-version="$mysql_version" --sandbox-binary ${PWD}/sandbox/binary
+  gh-ost-ci-env/bin/linux/dbdeployer unpack gh-ost-ci-env/mysql-tarballs/"$mysql_version".tar.xz --sandbox-binary ${PWD}/sandbox/binary

  mkdir -p sandboxes
  rm -rf sandboxes/*

-  if echo "$mysql_version" | egrep "5[.]5[.]" ; then
+  local mysql_version_num=${mysql_version#*-}
+  if echo "$mysql_version_num" | egrep "5[.]5[.]" ; then
    gtid=""
  else
    gtid="--gtid"
  fi
-  gh-ost-ci-env/bin/linux/dbdeployer deploy replication "$mysql_version" --nodes 2 --sandbox-binary ${PWD}/sandbox/binary --sandbox-home ${PWD}/sandboxes ${gtid} --my-cnf-options log_slave_updates --my-cnf-options log_bin --my-cnf-options binlog_format=ROW --sandbox-directory rsandbox
+  gh-ost-ci-env/bin/linux/dbdeployer deploy replication "$mysql_version_num" --nodes 2 --sandbox-binary ${PWD}/sandbox/binary --sandbox-home ${PWD}/sandboxes ${gtid} --my-cnf-options log_slave_updates --my-cnf-options log_bin --my-cnf-options binlog_format=ROW --sandbox-directory rsandbox

  sed '/sandboxes/d' -i gh-ost-ci-env/bin/gh-ost-test-mysql-master
  echo 'sandboxes/rsandbox/m "$@"' >> gh-ost-ci-env/bin/gh-ost-test-mysql-master
@ -59,12 +66,26 @@ test_mysql_version() {
  find sandboxes -name "stop_all" | bash
 }

-echo "Building..."
-. script/build
-# Test all versions:
-find gh-ost-ci-env/mysql-tarballs/ -name "*.tar.gz" | while read f ; do basename $f ".tar.gz" ; done | sort -r | while read mysql_version ; do
-  echo "found MySQL version: $mysql_version"
-done
-find gh-ost-ci-env/mysql-tarballs/ -name "*.tar.gz" | while read f ; do basename $f ".tar.gz" ; done | sort -r | while read mysql_version ; do
-  test_mysql_version "$mysql_version"
-done
+main() {
+  fetch_ci_env
+  test_dbdeployer
+
+  echo "Building..."
+  . script/build
+
+  # TEST_MYSQL_VERSION is set by the replica-tests CI job
+  if [ -z "$TEST_MYSQL_VERSION" ]; then
+    # Test all versions:
+    find gh-ost-ci-env/mysql-tarballs/ -name "*.tar.xz" | while read f ; do basename $f ".tar.xz" ; done | sort -r | while read mysql_version ; do
+      echo "found MySQL version: $mysql_version"
+    done
+    find gh-ost-ci-env/mysql-tarballs/ -name "*.tar.xz" | while read f ; do basename $f ".tar.xz" ; done | sort -r | while read mysql_version ; do
+      test_mysql_version "$mysql_version"
+    done
+  else
+    echo "found MySQL version: $TEST_MYSQL_VERSION"
+    test_mysql_version "$TEST_MYSQL_VERSION"
+  fi
+}
+
+main
--- a/script/ensure-go-installed
+++ b/script/ensure-go-installed
@ -1,7 +1,7 @@
 #!/bin/bash

-PREFERRED_GO_VERSION=go1.14.7
-SUPPORTED_GO_VERSIONS='go1.1[456]'
+PREFERRED_GO_VERSION=go1.16.4
+SUPPORTED_GO_VERSIONS='go1.1[56]'

 GO_PKG_DARWIN=${PREFERRED_GO_VERSION}.darwin-amd64.pkg
 GO_PKG_DARWIN_SHA=0f215de06019a054a3da46a0722989986c956d719c7a0a8fc38a5f3c216d6f6b
--- a/script/test
+++ b/script/test
@ -13,5 +13,6 @@ script/build

 cd .gopath/src/github.com/github/gh-ost

+# TODO: remove GO111MODULE once gh-ost uses Go modules
 echo "Running unit tests"
-go test ./go/...
+GO111MODULE=off go test ./go/...
--- a/test.sh
+++ b/test.sh
@ -5,7 +5,10 @@ retval=0
 for testsuite in base mysql sql
 do
  pushd go/${testsuite} > /dev/null;
-  go test $*;
+
+  # TODO: remove GO111MODULE once gh-ost uses Go modules
+  GO111MODULE=off go test $*;
+
  [ $? -ne 0 ] && retval=1
  popd > /dev/null;
 done
--- a/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go
+++ b/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go
@ -117,6 +117,19 @@ func (this *RowMap) GetUintD(key string, def uint) uint {
 	return uint(res)
 }

+func (this *RowMap) GetUint64(key string) uint64 {
+	res, _ := strconv.ParseUint(this.GetString(key), 10, 0)
+	return res
+}
+
+func (this *RowMap) GetUint64D(key string, def uint64) uint64 {
+	res, err := strconv.ParseUint(this.GetString(key), 10, 0)
+	if err != nil {
+		return def
+	}
+	return uint64(res)
+}
+
 func (this *RowMap) GetBool(key string) bool {
 	return this.GetInt(key) != 0
 }
 @ -1 +1 @@
 .1.0
 .1.2
				`@ -0,0 +1 @@`
				`--alter="change e e varchar(32) not null default ''"`