[Pgpool-general] Re: Bad degeneration when shutting down secondary backend

[Tatsuo Ishii]

> > Unfortunately pgpool's data difference detection is not perfect, and
> > sometimes it raise false alarm. That's why I recommend setting
> > replication_stop_on_mismatch to false.
> 
> The point here is that, if I shut down the secondary backend in a working
> production environment, degeneration mode performs in the wrong way
> (shutting down the master backend instead of the secondary). As a result,
> the entire environment would be down (secondary is down and master is shut
> down by pgpool).
> This behaviour may be avoided by setting "replication_stop_on_mismatch" to
> false, but on the other hand, if a real data mismatch exist, it won't be
> detected.
> Is there any other way to avoid pgpool detection of a data mismatch when one
> backend is being shut down?

If it's a schedule down time, you could use "switch" to tell pgpool
explicitly the secondary server is going down.

$ pgpool -s secondary switch

Does this help?
--
Tatsuo Ishii