On Thu, Nov 15, 2012 at 2:44 PM, Vlad <marchenko@xxxxxxxxx> wrote: > >> >> yeah. ok, nest steps: >> *) can you confirm that postgres process is using high cpu (according >> to top) during stall time > > > yes, CPU is spread across a lot of postmasters > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 29863 pgsql 20 0 3636m 102m 36m R 19.1 0.3 0:01.33 postmaster > 30277 pgsql 20 0 3645m 111m 37m R 16.8 0.3 0:01.27 postmaster > 11966 pgsql 20 0 3568m 22m 15m R 15.1 0.1 0:00.66 postmaster > 8073 pgsql 20 0 3602m 60m 26m S 13.6 0.2 0:00.77 postmaster > 29780 pgsql 20 0 3646m 115m 43m R 13.6 0.4 0:01.13 postmaster > 11865 pgsql 20 0 3606m 61m 23m S 12.8 0.2 0:01.87 postmaster > 29379 pgsql 20 0 3603m 70m 30m R 12.8 0.2 0:00.80 postmaster > 29727 pgsql 20 0 3616m 77m 31m R 12.5 0.2 0:00.81 postmaster > >> >> *) if, so, please strace that process and save some of the log > > > https://dl.dropbox.com/u/109778/stall_postmaster.log ok, excellent. reviewing the log, this immediately caught my eye: recvfrom(8, "\27\3\1\0@", 5, 0, NULL, NULL) = 5 recvfrom(8, "\327\327\nl\231LD\211\346\243@WW\254\244\363C\326\247\341\177\255\263~\327HDv-\3466\353"..., 64, 0, NULL, NULL) = 64 select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 2000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 3000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 4000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 6000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 7000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 8000}) = 0 (Timeout) select(0, NULL, NULL, NULL, {0, 9000}) = 0 (Timeout) semop(41713721, {{2, 1, 0}}, 1) = 0 lseek(295, 0, SEEK_END) = 0 lseek(296, 0, SEEK_END) = 8192 this is definitely pointing to spinlock issue. see: slock.c what you are seeing here is a backend getting caught in a spin loop via a stuck spinlock. 0-9 = 10 times. did you by any chance check the logs? did any backends restart? we are looking for this: elog(PANIC, "stuck spinlock (%p) detected at %s:%d", lock, file, line); Anything else going on in the log? The way to enable locks status is via LWLOCK_STATS macro. But before doing any thing plz check logs for error/panic. merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
