Re: Debugging a backend stuck consuming CPU

On Thu, May 19, 2016 at 8:46 AM, ktm@rice.edu <ktm@rice.edu> wrote:
> Hi PostgreSQL community,
>
> I am investigating a problem with a backend that appears to be stuck
> and spinning while performing a "DISCARD ALL" command. The system is
> running an older release 9.2.2. Are there any bugs that could be
> causing this behavior? How can I tell what the process is actually
> doing? It does not respond to either pg_cancel_backend() or to
> pg_terminate_backend() so it is acting like it is not receiving the
> signals. Any ideas on how to debug this would be appriciated.

1. Grab a stack trace and a 'perf top' for forensic analysis in case
it happens again
2. Install latest 9.2 binaries
3. Restart database

There's not much value in analyzing such an out of date database;
there's a very high probability your bug has already been fixed.

merlin