On Tue, Aug 31, 2021 at 11:41 AM hubert depesz lubaczewski <dep...@depesz.com> wrote: > > On Mon, Aug 30, 2021 at 09:09:20PM +0200, Laurenz Albe wrote: > > On Mon, 2021-08-30 at 17:18 +0200, hubert depesz lubaczewski wrote: > > > The thing is - I can't close it with pg_terminate_backend(), and I'd > > > rather not kill -9, as it will, I think, close all other connections, > > > and this is prod server. > > > > Of course the cause should be fixed, but to serve your immediate need: > > > > After calling pg_terminate_backend(), you can attach gdb to the backend and > > then run > > > > print ProcessInterrupts() > > > > That will cause the backend to exit normally without crashing the server. > > I got this mail too late, and the decision was made to restart Pg. After > restart all cleaned up nicely. > > So, while I can't help more with diagnosing the problem, I think it > might be good to try to figure out what could have happened. >
One possibility could be there are quite a few DDLs happening in this application at some particular point in time which can lead to high CPU usage. Prior to commit d7eb52d718 in PG-14, we use to execute all invalidations at each command end during logical decoding which might lead to such behavior temporarily. I think a bit of debugging when it shows this symptom could help us to identify if it is the problem I am speculating here. -- With Regards, Amit Kapila.
