Re: checkpoint_timeout

We have a transactional D.B writing directly to postgres (8.3) and these parameters have worked ok for us

checkpoint_timeout = 5min
checkpoint_segments = 10
wal_buffers = 1024kB

Date: Wed, 8 Oct 2008 12:34:00 -0200
From: rafael(dot)domiciano(at)gmail(dot)com
To: bnichols(at)ca(dot)afilias(dot)info
Subject: Re: [ADMIN] checkpoint_timeout
CC: chirag(dot)dave(at)gmail(dot)com; pgsql-admin(at)postgresql(dot)org

Hello Brad,
All of my bgwriter parameters is set on default. Following:#bgwriter_delay = 200ms # 10-10000ms between rounds#bgwriter_lru_percent = 1.0 # 0-100% of LRU buffers scanned/round
#bgwriter_lru_maxpages = 5 # 0-1000 buffers max written/round#bgwriter_all_percent = 0.333 # 0-100% of all buffers scanned/round#bgwriter_all_maxpages = 5 # 0-1000 buffers max written/round

I am trying now to increase the checkpoint_segments to 40...
2008/10/8 Brad Nicholson <bnichols(at)ca(dot)afilias(dot)info>

On Wed, 2008-10-08 at 10:31 -0200, Rafael Domiciano wrote:

> The server is running Postgres 8.2.4

> When the server is doing too much operations like I, U or D the

> postgres stop a while each 5 min...!

> I mean "stopping" that I don't receive any response from postgres, and

> the process the all people are running stay there, waiting for

> something.

> I read a several names to it like: gap, stall, slowdown... I don't

> know the write expression for this situation.

The bgwriter was added to help alleviate this problem.

What are your settings for that? The solution may be to push dirty

buffers to disk more aggressively via the bgwriter so you have less work

to do at checkpoint time.

--

Brad Nicholson 416-673-4106

Database Administrator, Afilias Canada Corp.