My toolforge service (https://author-disambiguator.toolforge.org/) keeps becoming unavailable with hangs/502 Bad Gateway or other server errors a few minutes after I restart it, and I can't see what could be causing this. These errors don't show up in the error log, and the 502 responses don't show up in the access log (which has had very little traffic anyway - one request per minute at most usually?)
I can connect to the kubernetes pod with kubectl and everything looks normal,there's only a few processes listed in /proc, etc. But I can't get a response via the web after the first few minutes.
The problem seems to have started mid-day yesterday - see the monitor data here:
with the surge in 4xx and 5xx status codes on 1/3 (by the way, I don't see the surge in 4xx status codes in access.log recently either - there are 2 from this morning and none yesterday, nothing like the multiple per second indicated in that grafana chart!)
I've restarted the service three times today; each time it worked for maybe 2 minutes, then froze up like this again. There's almost no traffic in the logs from anybody else (essentially the tool is broken right now).
Any ideas what's going on? This looks like some sort of upstream issue with nginx maybe?
I am seeing a "You have run out of local ports" error in the error logs from earlier today (but it hasn't repeated recently) which is maybe a clue? I don't think that could possibly be from anything my service is doing though!
I queried the cloud services mailing list on this and Brooke suggested T271063 might be related? The timing is at least coincidental.
Steps to Reproduce:
Go to https://author-disambiguator.toolforge.org/
no response, then 502 or 503 server error
The home page of the tool!