[pgpool-committers: 5790] pgpool: Second part for [pgpool-hackers: 3295] duplicate failover reque

[Muhammad Usama]

Second part for [pgpool-hackers: 3295] duplicate failover request ...fix

As per the discussion on the thread [pgpool-hackers: 3295] we came to the
conclusion, that the master watchdog node should resign from master
responsibilities if the primary backend node gets into quarantine state on that.

The commit implements the said behaviour by making the master/coordinator watchdog
node resign from its status if it fails to get the consensus for the quarantined
primary node failover, with in FAILOVER_COMMAND_FINISH_TIMEOUT(15) seconds.

When the watchdog master resigns, because of quarantined primary node its
wd_priority is decreased to (-1), so that it should get the least preference
in the next election for the master/coordinator node selection. And once the
election is concluded the wd_priority for the node gets restored to the
original configured value.

In case of failed consensus for standby node failover no action is taken.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=33df0d33df1ce701f07fecaeef5b87a2707c08f2

Modified Files
--------------
src/watchdog/watchdog.c | 47 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)