Evaluate AWS RDS Proxy for recommendation

AWS RDS Proxy is their PgBouncer equivalent for Database Pooling.

Before proceeding there's some verification required around compatibility, namely:

• Is it 100% Postgres compliant and does it support everything GitLab requires in terms of it's database connection. This is a functional question we would need the Database team to lean in on. We specifically must avoid another situation like AWS Aurora.
  • Does it's listed limitations impact GitLab
• Will it maintain aligned version compatibility. Previously RDS Proxy did not support the latest versions of Postgres.
• Authentication guidance will be required from it's requirement to use AWS Secrets Manager (which in turn requires a new IAM role) through to authentication type (SCRAM, etc...)
• Performance testing will be required to ensure the pooler does not itself become a bottleneck
• How do we handle it's lack of support for Read Replicas