Re: Unintended restart after recovery error

Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:

> On Wed, Nov 12, 2014 at 6:52 PM, Antonin Houska <ah(at)cybertec(dot)at> wrote:
> > While looking at postmaster.c:reaper(), one problematic case occurred to me.
> >
> >
> > 1. Startup process signals PMSIGNAL_RECOVERY_STARTED.
> >
> > 2. Checkpointer process is forked and immediately dies.
> >
> > 3. reaper() catches this failure, calls HandleChildCrash() and thus sets
> > FatalError to true.
> >
> > 4. Startup process exits with non-zero status code too - either due to SIGQUIT
> > received from HandleChildCrash or due to some other failure of the startup
> > process itself. However, FatalError is already set, because of the previous
> > crash of the checkpointer. Thus reaper() does not set RecoveryError.
> >
> > 5. As RecoverError failed to be set to true, postmaster will try to restart
> > the cluster, although it apparently should not.
>
> Why shouldn't postmaster restart the cluster in that case?
>

At least for the behavior to be consistent with simpler cases of failed
recovery (e.g. any FATAL error in StartupXLOG), which end up not restarting
the cluster.

--
Antonin Houska
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt
Web: http://www.postgresql-support.de, http://www.cybertec.at