Otdfbt

I've installed GitLab on a CentOS 7 using the Omnibus installer a few months ago. It has ran fine but, today it started to throw a 503 error page when I visit the main page to login.

I ran the gitlab-ctl status command and I don't see anything jumping out at me that shows there is a problem. Does anyone know where to go from here?

# gitlab-ctl status
run: alertmanager: (pid 4591) 14837s; run: log: (pid 4590) 14837s
run: gitaly: (pid 4580) 14837s; run: log: (pid 4579) 14837s
run: gitlab-monitor: (pid 4574) 14837s; run: log: (pid 4572) 14837s
run: gitlab-workhorse: (pid 4583) 14837s; run: log: (pid 4581) 14837s
run: logrotate: (pid 15028) 436s; run: log: (pid 4567) 14837s
run: nginx: (pid 4573) 14837s; run: log: (pid 4571) 14837s
run: node-exporter: (pid 4584) 14837s; run: log: (pid 4582) 14837s
run: postgres-exporter: (pid 4568) 14837s; run: log: (pid 4566) 14837s
run: postgresql: (pid 4593) 14837s; run: log: (pid 4592) 14837s
run: prometheus: (pid 4586) 14837s; run: log: (pid 4585) 14837s
run: redis: (pid 4562) 14837s; run: log: (pid 4560) 14837s
run: redis-exporter: (pid 4576) 14837s; run: log: (pid 4575) 14837s
run: sidekiq: (pid 4559) 14837s; run: log: (pid 4558) 14837s
run: unicorn: (pid 23104) 1s; run: log: (pid 4577) 14837s

I went on to use gitlab-ctl tail per suggestions in comments and found references to a stale unicorn pid file. Simply restarting all services with gitlab-ctl restart made the 503 error go away and all is well after that. Still not sure why unicorn decided to crash though.

I was able to fix the issue to get back up and running but, I'm unsure of the root cause.

first I used gitlab-ctl tail and found that there was a log message stating there was a stale unicorn PID file. This basically told me that unicorn application server had crashed for some reason or another.

I restarted all gitlab services with gitlab-ctl restart which takes a few minutes to properly shutdown and restart all services and eventually I was able to use GitLab under normal conditions again.