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Diffstat (limited to 'doc/update/background_migrations.md')
| -rw-r--r-- | doc/update/background_migrations.md | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/doc/update/background_migrations.md b/doc/update/background_migrations.md index a55d2af8dd4..be6ad43fa8a 100644 --- a/doc/update/background_migrations.md +++ b/doc/update/background_migrations.md @@ -124,8 +124,10 @@ If you get this error, [check the batched background migration options](#databas ### Pause batched background migrations in GitLab 14.x -To pause an ongoing batched background migration, use the `disable` command above. -This command causes the migration to complete the current batch, and then wait to start the next batch. +To pause an ongoing batched background migration, +[disable the batched background migrations feature](#enable-or-disable-background-migrations). +Disabling the feature completes the current batch of migrations, then waits to start +the next batch until after the feature is enabled again. Use the following database queries to see the state of the current batched background migration: @@ -201,6 +203,47 @@ To disable it: Feature.disable(:optimize_batched_migrations) ``` +### Parallel execution + +> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/104027) +> in GitLab 15.7, [behind a feature flag](../user/feature_flags.md), +> [enabled by default](https://gitlab.com/gitlab-org/gitlab/-/issues/372316). +> - Enabled on GitLab.com. +> - Recommended for production use. +> - For GitLab self-managed instances, GitLab administrators can opt to +> [disable it](#enable-or-disable-parallel-execution-for-batched-background-migrations). + +There can be [risks when disabling released features](../administration/feature_flags.md#risks-when-disabling-released-features). +Refer to this feature's version history for more details. + +To speed up the execution of batched background migrations, two migrations are executed at the same time. + +[GitLab administrators with access to the GitLab Rails console](../administration/feature_flags.md) can change +the number of batched background migrations executed in parallel: + +```ruby +ApplicationSetting.update_all(database_max_running_batched_background_migrations: 4) +``` + +#### Enable or disable parallel execution for batched background migrations + +Parallel execution for batched background migrations is under development but ready for production use. +It is deployed behind a feature flag that is **enabled by default**. +[GitLab administrators with access to the GitLab Rails console](../administration/feature_flags.md) +can opt to disable it. + +To enable it: + +```ruby +Feature.enable(:batched_migrations_parallel_execution) +``` + +To disable it: + +```ruby +Feature.disable(:batched_migrations_parallel_execution) +``` + ## Troubleshooting ### Enable or disable background migrations |