On 2017-11-06 15:35:03 -0500, Tom Lane wrote: > David Pacheco <dap@xxxxxxxxxx> writes: > > I ran into what appears to be a deadlock in the logging subsystem. It > > looks like what happened was that the syslogger process exited because it > > ran out of memory. But before the postmaster got a chance to handle the > > SIGCLD to restart it, it handled a SIGUSR1 to start an autovacuum worker. > > That also failed, and the postmaster went to log a message about it, but > > it's blocked on the pipe that's normally connected to the syslogger, > > presumably because the pipe is full because the syslogger is gone and > > hasn't read from it. > > Ugh. I'm somewhat inclined to say that one has to live with this if the system is so resource constrainted that processes barely using memory get killed. We could work around a situation like that if we made postmaster use a *different* pipe as stderr than the one we're handing to normal backends. If postmaster created a new pipe and closed the read end whenever forking a syslogger, we should get EPIPEs when writing after syslogger died and could fall back to proper stderr or such. Greetings, Andres Freund -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
