Help out in the deployment of GitLab 9.3
This issue is to flag the fact that the deployment of GitLab 9.3 required help and caused roughly 20m downtime.
We are investigating the root cause of the why the release of GitLab 9.3 was so problematic in https://gitlab.com/gitlab-com/infrastructure/issues/2114
Briefly speaking the reason why we had downtime was that one migration was too aggressive, driving the database into a non-responsive situation.