Re: Autovacuum daemon terminated by signal 11

Tom Lane wrote:

> Hmm.  This isn't very trustworthy for lack of debug symbols (what we're
> probably looking at are the nearest global function names before the
> actual locations).  However, it strongly suggests that something is
> broken in the active memory context, and the most likely explanations
> for that are either a memory clobber (eg overrunning the requested size
> of a chunk) or CurrentMemoryContext pointing at a context that was
> already freed.  The latter theory ties into the fact that it seems to be
> happening during transaction end.  But any such bug of either type
> should have been found years ago given that development is invariably
> done with CLOBBER_FREED_MEMORY enabled.
>
> Alvaro, any thoughts?  Remember this is 8.1.15.

Not really.  It seems like this must be happening on the vicinity of
process_whole_db(), which is a less used code path than do_autovacuum(),
so it's more likely to have bugs.  I don't see anything obviously wrong
though.

I note that process_whole_db is not changing to AutovacMemCxt the way
do_autovacuum() does, but I don't see any way that this could cause a
problem.

Hmm, vacuum() creates a new memory context under PortalContext, but I
don't see that one set anywhere on the autovacuum path ... is that
bogus?

The lack of debug symbols makes this all mere guesses though.  The
backtrace did not make a lot of sense to me.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support