[pgpool-general: 7537] Re: Strange behavior on switchover with detach_false_primary enabled
emond.papegaaij at gmail.com
Fri Apr 30 21:11:17 JST 2021
> >> I started to think that detach_false_primary should not active on
> >> other than leader watchdog node because standby watchdog node can be
> >> interrupted by other watchdog node and causes unexpected failover. I
> >> will investigate more.
> > I was in the middle of typing this, it seems we are in agreement: I'm
> > wondering why a node that is not the pgpool leader makes this decision
> > at all. Shouldn't the view of the database cluster be the same from
> > all pgpool nodes? I'm not that much at home in how the watchdog makes
> > its decisions, but to me it seems only the leader can make autonomous
> > decisions. A node may request the cluster status to be reviewed, but
> > for an automated detach, I would at least expect a quorum is needed.
> Attached is the patch which implement this:
> - only the leader watchdog node runs detach_false_primary
> - if a quorum does not exist, the leader node does not run detach_false_primary
This patch is a bit over my head. I'm not that much at home in the
internals of pgpool. I've started a dedicated build job to test our
application with pgpool master with this patch applied. As each run
takes several hours, and I might need a run or 2-3 to get things
right, I expect to get some results from this next week.
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