HTTPS repository service stops functioning sporadically
As reported by Alexander Hahn, cloning (and any other git operation transported via https) stops working sporadically, as git clone over https fails by eventual timeout.
Operations over ssh transport are unaffected.
This is fixed by gitlab-ctl restart, but should not be necessary. The reason for this behaviour is as yet unknown.
NB: ohwr.org showed an uptime of 188 days. I just rebooted the machine. Wait and see.