Validate and deploy PostgreSQL 12.9
We are currently running PostgreSQL v12.7 in production.
Per @NikolayS
, PostgreSQL v12.9 is expected to be out this Thursday, November 11, and will contain a crucial fix for subtransaction performance issues that we have been seeing on occasion on GitLab.com: https://github.com/postgres/postgres/commit/05e6e78c1840d07154a4b52092178a2d1ad39445
Since upgrading from 12.7 to 12.9 is considered a minor release, we should be able to avoid a downtime upgrade, but we will want to validate that there aren't any other changes that adversely affect the system.
I propose we deploy and validate this upgrade to staging ASAP, and then look to rolling this out to production. Upgrading the replicas is a higher priority than the primary since this fix only affects replicas. However, I don't know if there are other changes that require upgrading both primary/secondaries around the same time.
Related issues:
- https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/14356
- https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/14358
/cc: @glopezfernandez, @Finotto