Re: Backends stuck in LISTEN

Marko Tiikkaja wrote:
> Hi people,
>
> Today we had a problem where around 30-40 backends were stuck in
> LISTEN for a long time.  I snatched a core dump before we had to
> kill the server, and the backtrace looks like this:
>
> #0  0x00007f26dd17d5b7 in monstartup () from /lib/x86_64-linux-gnu/libc.so.6
> #1  0x00007f26d79e5c70 in ?? ()
> #2  0x00007f26d79e5c80 in ?? ()
> #3  0x00007f254d772b60 in ?? ()
> #4  0x00000000006359c5 in LWLockAcquire (lockid=87, mode=LW_SHARED)
> at /build/buildd/postgresql-9.1-9.1.9/build/../src/backend/storage/lmgr/lwlock.c:464

Hm, looks like either they got stuck trying to activate profiling (but
then Debian doesn't build its packages with gcc -pg, does it?), or the
backtrace is flawed for those upper frames.  Maybe installing the libc
-dbg (I imagine it'd be libc6-dbg) package would be useful, if this
reoccurs.

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services