We saw in production that DispatchWorker was running about twice an hour,
which would schedule twice as many jobs as it should.
For some reason, BatchWorker was running 1000 times per hour, possibly
due to Sidekiq RSS kills that caused these jobs to restart.
Adding an ExclusiveLease prevents these jobs from running more
than they should.
Relates to https://gitlab.com/gitlab-com/infrastructure/issues/4526
A repo does not need pushes before it will be repo-checked. There are
other sources where commits can come from (e.g. import or webIDE).
In the test I made the method of breaking a repo more robust. And
added a few test examples.
See also gitlab-org/gitlab-ce#45046.
Dumping too many jobs in the same queue (e.g. the "default" queue) is a
dangerous setup. Jobs that take a long time to process can effectively
block any other work from being performed given there are enough of
these jobs.
Furthermore it becomes harder to monitor the jobs as a single queue
could contain jobs for different workers. In such a setup the only
reliable way of getting counts per job is to iterate over all jobs in a
queue, which is a rather time consuming process.
By using separate queues for various workers we have better control over
throughput, we can add weight to queues, and we can monitor queues
better. Some workers still use the same queue whenever their work is
related. For example, the various CI pipeline workers use the same
"pipeline" queue.
This commit includes a Rails migration that moves Sidekiq jobs from the
old queues to the new ones. This migration also takes care of doing the
inverse if ever needed. This does require downtime as otherwise new jobs
could be scheduled in the old queues after this migration completes.
This commit also includes an RSpec test that blacklists the use of the
"default" queue and ensures cron workers use the "cronjob" queue.
Fixesgitlab-org/gitlab-ce#23370
Yorick Peterse