Re: pg_stop_backup does not complete

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Josh Berkus <josh@agliodbs.com>, Greg Smith <greg@2ndQuadrant.com>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-02-25T00:08:18Z
Lists: pgsql-hackers
Simon Riggs <simon@2ndQuadrant.com> writes:
> On Wed, 2010-02-24 at 16:52 -0500, Tom Lane wrote:
>> * emit a NOTICE as soon as pg_stop_backup's actual work is done and
>> it's starting to wait for the archiver (or maybe after it's waited
>> for a few seconds, but much less than the present 60).

> Pointless really. Nobody runs backups in production by typing
> pg_stop_backup() except in a demo. Nobody will see this. 

I agree it's pointless in production, but this isn't about production,
it's about friendliness to people who are experimenting.  The case will
probably never come up in production because a production installation
should have a non-broken archive_command.

>> * extend the existing WARNING (and the NOTICE too if we elect to have
>> one) with a HINT message explicitly saying that you can cancel the
>> wait but thus-and-such consequences might ensue.

> If you can see the HINT, you can also see the WARNING. If you can see
> the WARNING and do nothing, I don't think we need a "objects in the
> mirror may be closer than they appear" message. If people can't work out
> that if a) they are running something and b) that something is waiting
> that they should cancel it then we aren't going to have much luck with
> them.

The value of the HINT I think would be to make them (a) not afraid to
hit control-C and (b) aware of the fact that their archiver has got
a problem.

			regards, tom lane