But it appears that the fail condition for "watchdog" is the failure of a pgpool-II instance. In the configuration described in the wiki you would put a pgpool-II instance on each Postgres node, and if one of the pgpool-II instances fails it executes a script (which can create the trigger file to promote the standby to master). However, if the fail condition for watchdog is a failure of the pgpool-II instance what happens if the DBMS has availability issues but the pgpool-II process on that server is ok? The fail condition would never be triggered, right?
Will J. Dunn
On Tue, Jul 21, 2015 at 4:27 PM, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> wrote:
On 07/21/2015 01:21 PM, William Dunn wrote:
That's pretty cool! But the intended use of watchdog is so you can have
multiple pgpool-II instances and failover among them
(http://www.pgpool.net/docs/latest/pgpool-en.html#watchdog) rather than
failure of Postgres. In the configuration described in that wiki what
happens when the DBMS goes down but pgpool-II is fine? The watchdog
appears to be monitoring the pgpool-II process, not the
postgres/postmaster process.
>From what I see, it has the ability to execute a command/script based on a failed condition which could include but not be limited to a command to fail over a standby.
JD
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