Hanns Hartman <hwhartman@gmail.com> writes:
> I'm running postgres 8.3.17 on a redhat linux mips derivative and I've
> observed a postgres crash and the subsequent messages in my postgres
> debug log.
> 2011-12-21 19:08:49 UTC - LOG: shutting down
> 2011-12-21 19:08:49 UTC - PANIC: concurrent transaction log activity
> while database system is shutting down
> 2011-12-21 19:08:49 UTC - LOG: background writer process (PID 1423)
> was terminated by signal 6: Aborted
> 2011-12-21 19:08:49 UTC - LOG: terminating any other active server processes
Best guess is that something sent the background writer process a
SIGUSR2 signal. The first two messages indicate that it received such
a signal, tried to shut down, and panicked when it noticed that other
processes were still writing to xlog. The postmaster wouldn't (or at
least shouldn't, and hasn't been observed to) send such a signal while
it still has other live children, so I think you ought to look around
for other possible sources of a signal.
regards, tom lane