On 2018-08-04 10:54:22 +0100, Simon Riggs wrote:
> On 4 August 2018 at 07:56, Michael Paquier <michael@paquier.xyz> wrote:
> >> Sounds like we should write a pending timeline change to the control
> >> file and have pg_rewind check that instead.
> >>
> >> I'd call this a timing bug, not a doc issue.
> >
> > Well, having pg_rewind enforce a checkpoint on the promoted standby
> > could cause a performance hit as well if we do it mandatorily as if
> > there is delay between the promotion and the rewind triggerring a
> > checkpoint could have already happen. So it is for me a documentation
> > bug first regarding the failover workflow, and potentially a patch for a
> > new feature which makes pg_rewind trigger directly a checkpoint.
>
> pg_rewind doesn't work correctly. Documenting a workaround doesn't change that.
Especially because most people will only understand this after they've
been hit, as test scenarios will often just be quick enough.
Greetings,
Andres Freund