From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Fujii Masao <masao(dot)fujii(at)gmail(dot)com> |
Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: failover vs. read only queries |
Date: | 2010-06-09 14:41:25 |
Message-ID: | 24621.1276094485@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Fujii Masao <masao(dot)fujii(at)gmail(dot)com> writes:
> 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. This looks like 9.1 material to me, and besides I'm not even
convinced that what you propose is a good solution.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2010-06-09 14:43:11 | Re: Invalid YAML output from EXPLAIN |
Previous Message | Heikki Linnakangas | 2010-06-09 14:38:56 | Re: [BUGS] Server crash while trying to read expression using pg_get_expr() |