Re: master in standby mode croaks

On Wed, Apr 14, 2010 at 4:21 AM, Simon Riggs <simon(at)2ndquadrant(dot)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.

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.

...Robert