Re: Postgres 8.4.20 seqfault on RHEL 6.4

On Thu, Feb 12, 2015 at 4:33 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Dave Johansen <davejohansen@gmail.com> writes:
> I'm running Postgres 8.4.20 on RHEL 6.4 and it will occasionally crash. The
> postgres.log file just says that a PID was terminated. The output from
> dmesg has a message like this one:
> postmaster[22905]: segfault at 686 ip 0000000000000686 sp 00007fff83d72e88
> error 14 in postgres[400000+463000]

> What can I do to try and figure out what is causing the crash and fix it?

(1) install relevant postgresql-debuginfo package (assuming we're talking
about a Red Hat-originated postgres package)

(2) run postmaster under "ulimit -c unlimited" (easiest way is probably
to add such a command to /etc/rc.d/init.d/postgresql and restart the
service)

(3) wait for crash

(4) gdb the resulting corefile (should be under your $PGDATA directory)

(5) send in a stack trace.

Here's the stacktrace from gdb (if it matters, the package version from RHEL is postgresql-8.4.18-1.el6_4.x86_64):

#0  0x0000000000000686 in ?? ()

#1  0x00007f76ae551801 in ?? ()

#2  0x00000000019f7793 in ?? ()

#3  0x00007fff06ad6be0 in ?? ()

#4  0x00007fff06ad6be0 in ?? ()

#5  0x0000000000545e35 in ExecMakeFunctionResult (fcache=0x19f5680, econtext=0x19f37e8, isNull=0x19f7793 "", isDone=0x19f7b8c) at execQual.c:1870

#6  0x0000000000541096 in ExecTargetList (projInfo=<value optimized out>, isDone=0x7fff06ad704c) as execQual.c:5212

#7  ExecProject (projeInfo=<value optimized out>, isDone=0xfff06ad704c) as execQual.c:5427

#8  0x0000000000553c5b in ExecResult (node=0x1999a68) at nodeResult.c:155

#9  0x00000000005406c8 in ExecProcNode (node=0x1999a68) at execProcnode.c:344

#10 0x000000000053e942 in ExecutePlan (queryDesc=0x1990c60, direction=<value optimized out>, count=0) as execMain.c:1542

#11 0xstandardExecutorRun (queryDesc=0x1990c60, direction=<value optimized out>, count=0) as execMain.c:310

... (I can include the rest, if it's needed)

Any insight?
Thanks,
Dave