Re: [PATCH] Log crashed backend's query (activity string)

On Tue, Sep 6, 2011 at 5:34 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Marti Raudsepp <marti(at)juffo(dot)org> writes:
>> This patch adds the backend's current running query to the "backend
>> crash" message.
>
> Sorry, this patch is entirely unacceptable.  We cannot have the
> postmaster's functioning depending on the contents of shared memory
> still being valid ... most especially not when we know that somebody
> just crashed, and could have corrupted the shared memory in arbitrary
> ways.  No, I don't think your attempts to validate the data are
> adequate, nor do I believe they can be made adequate.

Why and why not?

> And I doubt
> that the goal is worth taking risks for.

I am unable to count the number of times that I have had a customer
come to me and say "well, the backend crashed". And I go look at
their logs and I have no idea what happened. So then I tell them to
include %p in log_line_prefix and set log_min_duration_statement=0 and
call me if it happens again. This is a huge nuisance and a serious
interference with attempts to do meaningful troubleshooting. When it
doesn't add days or weeks to the time to resolution, it's because it
prevents resolution altogether. We really, really need something like
this.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company