Re: server crash with "process 22821 releasing ProcSignal slot 32, but it contains 0"

Merlin Moncure <mmoncure@gmail.com> writes:
> 2012-06-25 09:08:08 CDT [postgres@ysanalysis_hes]: LOG:  could not
> send data to client: Broken pipe
> 2012-06-25 09:08:10 CDT [postgres@ysanalysis_hes]: LOG:  unexpected
> EOF on client connection
> 2012-06-25 09:08:10 CDT [postgres@ysanalysis_hes]: LOG:  process 22821
> releasing ProcSignal slot 32, but it contains 0
> 2012-06-25 09:08:10 CDT [postgres@ysanalysis_hes]: LOG:  failed to
> find proc 0x7f48617e2ab0 in ProcArray
> [and a bit later]
> 2012-06-25 09:08:24 CDT [postgres@ysanalysis_hes]: FATAL:  latch already owned

I think what we're looking at here is a screw-up in the process shutdown
sequence.  Perhaps caused by bad recovery from an attempt to send an
error message to the already-disconnected client; but that's just
speculation, and it's hard to see how to get more info without a core
dump.

I wonder whether we shouldn't promote some or all of these three error
cases to PANIC, as they certainly suggest shared-memory corruption.
And if it did panic, we could hope to get a core dump for debugging
purposes.

            regards, tom lane