Use structured logging for DB load balancer
All threads resolved!
Relates to https://gitlab.com/gitlab-org/gitlab-ee/issues/13547 and https://gitlab.com/gitlab-org/gitlab-ee/issues/13548
CE backport of doc changes: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/32051
If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:
@gitlab-com/gl-security/appsec