* v1.1.0
* WIP: copying AUTO_INCREMENT value to ghost table
Initial commit: towards setting up a test suite
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
* greping for 'expect_table_structure' content
* Adding simple test for 'expect_table_structure' scenario
* adding tests for AUTO_INCREMENT value after row deletes. Should initially fail
* clear event beforehand
* parsing AUTO_INCREMENT from alter query, reading AUTO_INCREMENT from original table, applying AUTO_INCREMENT value onto ghost table if applicable and user has not specified AUTO_INCREMENT in alter statement
* support GetUint64
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
* minor update to test
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
* adding test for user defined AUTO_INCREMENT statement
Co-authored-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
The TABLE_SCHEMA and TABLE_NAME are already guaranteed to have the same value in COLUMNS and UNIQUES because of the WHEREs in each query. Dropping it from the ON clause makes it complete much faster.
On (at least) MySQL 5.6 installs with thousands of tables, this query completes in a few seconds without the additional join conditions, but takes more than a minute with it.
There is no need to call `applyColumnTypes` more than once for the same
`databaseName` and `tableName`, it is just move the additional
`columnList` to the first call.
The given `columnLists` may not contain all columns available in the
given table. This patch prevents the code to fail. Before this patch the
code was panicking whenever it was trying to set a value into a `nil`
object, e.g. `columnList.GetColumn('non-existant').Type = SomeType`.
For some reason the application was not completely failing but as a
side-effect any column after the non-existant column would never get its
Type properly set.
Both Percona and Maria allow MySQL to be configured to listen on an extra port when their thread pool is enable.
* https://www.percona.com/doc/percona-server/5.7/performance/threadpool.html
* https://mariadb.com/kb/en/the-mariadb-library/thread-pool-in-mariadb-51-53/
This is valuable because if the table has a lot of traffic (read or write load), gh-ost can end up starving the thread pool as incomming connections are immediately blocked.
By using gh-ost on the extra port, MySQL locking will still behave the same, but MySQL will keep a dedicated thread for each gh-ost connection.
When doing this, it's important to inspect the extra-max-connections variable. Both Percona and Maria default to 1, so gh-ost may easily exceed with its threads.
An example local run using this
```
$ mysql -S /tmp/mysql_sandbox20393.sock -e "select @@global.port, @@global.extra_port"
+---------------+---------------------+
| @@global.port | @@global.extra_port |
+---------------+---------------------+
| 20393 | 30393 |
+---------------+---------------------+
./bin/gh-ost \
--initially-drop-ghost-table \
--initially-drop-old-table \
--assume-rbr \
--port="20395" \
--assume-master-host="127.0.0.1:30393" \
--max-load=Threads_running=25 \
--critical-load=Threads_running=1000 \
--chunk-size=1000 \
--max-lag-millis=1500 \
--user="gh-ost" \
--password="gh-ost" \
--database="test" \
--table="mytable" \
--verbose \
--alter="ADD mynewcol decimal(11,2) DEFAULT 0.0 NOT NULL" \
--exact-rowcount \
--concurrent-rowcount \
--default-retries=120 \
--panic-flag-file=/tmp/ghost.panic.flag \
--postpone-cut-over-flag-file=/tmp/ghost.postpone.flag \
--execute
```
