Re: Streaming replication, and walsender during recovery
Simon Riggs <simon@2ndquadrant.com>
From: Simon Riggs <simon@2ndQuadrant.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-01-29T08:41:19Z
Lists: pgsql-hackers
On Fri, 2010-01-29 at 17:31 +0900, Fujii Masao wrote: > On Fri, Jan 29, 2010 at 4:13 AM, Simon Riggs <simon@2ndquadrant.com> wrote: > > Hmm, I'm sorry but that's bogus. Retaining so much WAL that we are > > strongly in danger of blowing disk space is not what I would call a > > safety feature. Since there is no way to control or restrain the number > > of files for certain, that approach seems fatally flawed. Reducing > > checkpoint_timeout is the opposite of what you would want to do for > > performance. > > Why do you worry about that only in the standby? I don't. The "safety feature" we just added makes it much more likely that this will happen on standby. > To improve the situation, I think that we need to use > checkpoint_segment/timeout as a trigger of restartpoint, regardless > of the checkpoint record. Though I'm not sure that is possible and > should be included in v9.0. Yes, that is a simple change. I think it is needed now. -- Simon Riggs www.2ndQuadrant.com