From: Simon Riggs <simon@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: cedric@dreamgnu.com
Cc: pgsql-performance@postgresql.org
Subject: Re: archive wal's failure and load increase.
Date: Fri, 29 Sep 2006 15:53:40 +0100
Message-ID: <1159541620.2649.10.camel@holly> (raw)
In-Reply-To: <15270.1159540162@sss.pgh.pa.us>
References: <451C2572.20800@dreamgnu.com>
<1159527513.2767.296.camel@holly>
<15270.1159540162@sss.pgh.pa.us>
On Fri, 2006-09-29 at 10:29 -0400, Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.com> writes:
> > We discussed putting PreallocXlogFiles() in bgwriter once before, but I
> > think last time we discussed that idea it was rejected, IIRC.
>
> We already do that: it's called a checkpoint.
Yes, but not enough.
PreallocXlogFiles() adds only a *single* xlog file, sometimes.
On a busy system, that would be used up too quickly to make a
difference. After that the effect of adding new files would continue as
suggested.
If it did add more than one... it might work better for this case.
> It's a good thought but I don't think the theory holds water for
> explaining Cedric's problem, unless there was *also* some effect
> preventing checkpoints from completing ... which would be a much more
> serious problem than the archiver failing.
Still the best explanation for me.
--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: simon@2ndquadrant.com, tgl@sss.pgh.pa.us, cedric@dreamgnu.com
Subject: Re: archive wal's failure and load increase.
In-Reply-To: <1159541620.2649.10.camel@holly>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox