Add support for configuring number of shards and replicas for gitlab-production-migrations index

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

• Close this issue

Proposal

In Advanced Search setup, add ability to configure gitlab-production-migrations index shards and replicas.

Without ability to adjust this index you cannot use AWS OpenSearch in recommended 3-AZ with Standby 99.99% resiliency mode.

When switching to this mode you get the following validation error

Validation errors
The following indices do not have multiples of 3 copies - gitlab-production-migrations.
Index should have 3 or multiples of 3 copies including primary and replica for 3-AZ with Standby.
Update the replica count for these indices and try again or reach out to AWS support.