I have an application behind nginx (Rails on Unicorn if it matters) which listens on a UNIX socket.
It all works nice, especially when load is low. When there is some load on the server though (say 70%), I randomly(?) get a bunch of 502 responses -- usually in batches.
Thus the question: when (under what conditions) does nginx send a 502 response?
Thanks in advance,
fastcatch
PS: The app's worker processes do not seem to be irresponsive, slow, blocked for IO or anything else I have been able to identify as a possible cause. Thus I want to understand more the nginx side so as to find the root cause -- which I believe is on the other side (or some config tweak needed soemwhere).
It all works nice, especially when load is low. When there is some load on the server though (say 70%), I randomly(?) get a bunch of 502 responses -- usually in batches.
Thus the question: when (under what conditions) does nginx send a 502 response?
Thanks in advance,
fastcatch
PS: The app's worker processes do not seem to be irresponsive, slow, blocked for IO or anything else I have been able to identify as a possible cause. Thus I want to understand more the nginx side so as to find the root cause -- which I believe is on the other side (or some config tweak needed soemwhere).