Re: master in standby mode croaks

On Wed, 2010-04-14 at 07:07 -0400, Robert Haas wrote:
> On Wed, Apr 14, 2010 at 4:21 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> > On Sat, 2010-04-10 at 09:02 -0400, Robert Haas wrote:
> >
> >> So this can fail in either of two ways
> >
> > If I understand this correctly, it is unconvincing as a failure mode
> > since it doesn't follow any of the documented procedures for creating a
> > standby. There are many ways to screw up that ignore the manual, which
> > is why the manual exists.
> >
> > If you can show a full test case, with failure, then I'll follow it
> > through.
> 
> Huh?  If I had done everything correctly, of course I wouldn't have
> gotten an error message at all.  Surely the point is that if I do
> something wrong, I should get an error message that describes what I
> actually did wrong rather than an error message telling me that I did
> something wrong which I clearly did not do.

I will change the error message.

> The recent patch to allow starting from a shutdown checkpoint means
> that a standby can be created by shutting down the master and taking a
> filesystem-level snapshot of the cluster directly, creating
> recovery.conf, and firing it up again.  Anyone who does that with the
> default postgresql.conf, though, is going to get a message telling
> them that they need to change a setting which is already set
> correctly.

Why would they do that? I would never claim this supports all use cases,
just the sensible ones.

-- Simon Riggs           www.2ndQuadrant.com