Re: How to avoid transaction ID wrap

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: Mark Woodward <pgsql(at)mohawksoft(dot)com>
Cc: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Zdenek Kotala <zdenek(dot)kotala(at)sun(dot)com>, Koichi Suzuki <suzuki(dot)koichi(at)oss(dot)ntt(dot)co(dot)jp>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: How to avoid transaction ID wrap
Date: 2006-06-08 14:59:42
Message-ID: 44883B5E.7030700@commandprompt.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Mark Woodward wrote:
>> On Wed, Jun 07, 2006 at 07:07:55PM -0400, Mark Woodward wrote:
>>> I guess what I am saying is that PostgreSQL isn't "smooth," between
>>> checkpoints and vacuum, it is near impossible to make a product that
>>> performs consistently under high load.
>> Have you tuned the bgwriter and all the vacuum_cost stuff? I've get to
>> find a case where I couldn't smooth out the IO load so that it wasn't an
>> issue.
>
> In several project that I have been involved with, PostgreSQL had most of
> the important features to be used, but in one project, checkpoints caused
> us to time out under load. In this current project I am researching, I
> know that vacuum may be an issue. The load is brutally constant.

I was recently involved in a project where we had to decrease the
checkpoint_timeout . The problem was, that the database was performing
so many transactions that if we waiting for 5 minutes, checkpoint would
take entirely too long.

We ended up doing checkpoints every two minutes which with the increase
in checkpoint_segments and adjustment of bgwriter settings would level
out the load.

Sincerely,

Joshua D. Drake

>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>

--

=== The PostgreSQL Company: Command Prompt, Inc. ===
Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240
Providing the most comprehensive PostgreSQL solutions since 1997
http://www.commandprompt.com/

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2006-06-08 15:01:01 Re: code cleanup for SearchSysCache
Previous Message Andrew Dunstan 2006-06-08 14:54:09 Re: Going for 'all green' buildfarm results