Resource saturation: web/workers saturation
Web service is regularly running our of unicorn workers, leading to high queue times, elevated latencies and 503s.
My best guess is that this is related to the Projects::MergeRequests::ContentController
endpoint, specifically its usage on GitLab.com.
The following graph shows how usage of Projects::MergeRequests::ContentController
has escalated since the beginning of October.
Related https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/8407