Re: failover vs. read only queries

> When the trigger file is created while the recovery keeps
> waiting for the release of the lock by read only queries,
> it might take a very long time for the standby to become
> the master. The recovery cannot go ahead until those read
> only queries have gone away. This would increase the downtime
> at the failover, and degrade the high availability.
>
> To fix the problem, when the trigger file is found, I think
> that we should cancel all the running read only queries
> immediately (or forcibly use -1 as the max_standby_delay
> since that point) and make the recovery go ahead. If some
> people prefer queries over failover even when they create the
> trigger file, we can make the trigger behavior selectable in
> response to the content of the trigger file like pg_standby
> does.
>
> This problem looks like a bug, so I'd like to fix that for
> 9.0. But the amount of code change might not be small.
> Thought?

+1. Down time of HA system is really important for HA users.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp