Re: fast promotion and log_checkpoints

On 1 May 2013 10:05, Fujii Masao <masao.fujii@gmail.com> wrote:

> In HEAD, when the standby is promoted, recovery requests the checkpoint
> but doesn't wait for its completion. I found the checkpoint starting log message
> of this checkpoint looks odd as follows:
>
>     LOG:  checkpoint starting:
>
> I think something like the following is better.
>
>     LOG:  checkpoint starting: end-of-recovery
>
> In 9.2 or before, "end-of-recovery" part is logged. Even if we changed the
> behavior of end-of-recovery checkpoint, I think that it's more intuitive to
> label it as "end-of-recovery". Thought?

The checkpoint isn't an "end-of-recovery" checkpoint, its just the
first checkpoint after the end of recovery. I don't think it should
say "end-of-recovery".

The problem is that we've now changed the code to trigger a checkpoint
in a place that wasn't part of the original design, so the checkpoint
called at that point isn't supplied with a reason and so has nothing
to print.

It would be possible to redesign this with a special new reason, or we
could just use "time" as the reason, or we could just leave it.

Do nothing is easy, though so are the others, so we can choose
anything we want. What do we want it to say?

--Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services