Backend review guidelines from deployment problems
We've had a couple of things recently that are non-obvious (or at least, aren't obvious unless you already know that they can be a problem) that we can cover in reviews.
- Sidekiq queues and workers shouldn't be removed in a release - they should be kept for at least one release, to allow any existing jobs to be processed. https://gitlab.com/gitlab-org/gitlab-ce/issues/34223
- Changes to the type of a cached value must be approached with care, because we don't guarantee that the cache is being read from and written to by nodes using the same version. https://gitlab.com/gitlab-org/gitlab-ce/issues/35094
I think https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/code_review.md is great, but I wonder if we should update it with a specific section about GitLab.com concerns, including database and filesystem access as well as the points above?
@DouweM @rspeicher @rymai @grzesiek @dzaporozhets @stanhu - wdyt?