postmaster freeze

Vladimir Drobny <vladimir.drobny@vvexpert.sk> writes:

I have problem with my postgres server. I am running postgres
7.3.4 on RedHat9 (shrike) on dual processor machine.
Sometimes (cca 3 times per day) postmaster service will freeze
with 100% CPU load with SELECT statement (statement is never
finished). If I try the same action again without restarting
server, it works (but freezed postmasted still consume 100% CPU).
It seems that something in postgres is locked, because
if I run command vacuum when this situation happens,
psql will freeze too. I defined also statement_timeout=600000
(10 minutes) in config, but It seem does not work.

Hmm, are you able to "kill -9" the stuck backend? I'm wondering about
hardware or kernel-level problems. If kill doesn't work then the
problem is kernel or hardware.

If it does, then please try attaching to the stuck backend with gdb to
get a stack trace. That would give some clue what it's doing.

regards, tom lane