> > Does it attempt any interaction with Slony when it detects a failure of
the
> > master? It would seem a pity to have pgpool watching the pair to detect
> > failure but having to have a separate watcher process to tell Slony to
> > failover.
>
> If pgpool detects PostgreSQL failure, Slony should detect it as well, no?
Others are much better place to answer this, but my understanding is that
Slony does not do so:
http://gborg.postgresql.org/project/slony1/genpage.php?howto_overview
"What Slony-I is not:
Slony-I is not a network management system. Slony-I does not have any
functionality within it to detect a node failure, or automatically promote a
node to a master or other data origin. Slony-I is not multi-master; it's
not
a connection broker, and it doesn't make you coffee and toast in the
morning."
> pgpool 2.5 has the capabilty to perform periodical health checking to
> PostgreSQL.
Since pgpool has this capability, how about including a hook that allows a
script to be run when pgpool detects a problem with the master? That would
allow action to be taken to investigate further and, if required, switchover
or failover and promote the slave to master.
Julian Scarfe