[Pgpool-general] pgpool crash in realloc on freebsd

[Tatsuo Ishii]

> Hi All,
> 
> I'm attempting to use pgpool with a high-traffic website.  The majority of
> our queries are already cached, but I'm trying to use pgpool to limit the
> toll postgres' startup/teardown process takes on a per-connection basis.
> 
> I have pgpool functioning, but it's not reliable.  Some child processes are
> crashing with signal 6:
> 
> pid 43893 (pgpool), uid 0: exited on signal 6 (core dumped)
> pid 43848 (pgpool), uid 0: exited on signal 6 (core dumped)
> pid 43886 (pgpool), uid 0: exited on signal 6 (core dumped)
> pid 43987 (pgpool), uid 0: exited on signal 6 (core dumped)
> pid 44008 (pgpool), uid 0: exited on signal 6 (core dumped)
> 
> I did a quick backtrace (pasted below).
> 
> Does anyone have an idea why realloc may fail?  Pgpool is using only a small
> amount of memory, its being run without limits (ulimit unlimited) and the
> machine has plenty of spare RAM.
> 
> It's not using enough memory to get into FreeBSD's default maximum
> per-process (512MB).

It seems realloc tried to allocate 1009742944 bytes of memory. Of
course this should not happen. I think the cause of this was a broken
packet arrives from the frontend.

> #8  0x08051910 in SimpleForwardToFrontend (kind=48 '0', frontend=0x8071000,

There's no such a packet (kind = '0') according the PostgreSQL
docs. What kind of frontend are you using?
--
Tatsuo Ishii