Re: Checkpoint and Background Writer Statistics

Err, sorry, I think I meant bgwriter_lru_maxpages, not lru_max_dirty.
---
===========================
Samuel Nelson
Consistent State
www.consistentstate.com
303-955-0509
===========================

On Tue, Feb 22, 2011 at 3:42 PM, Sam Nelson <samn(at)consistentstate(dot)com>wrote:

> Hi, list.
>
> We're trying to pull a few various metrics from the postgres catalogs to
> analyze database performance, and included is buffers_checkpoint and
> buffers_clean from pg_stat_bgwriter.
>
> One of our clients has an lru_max_dirty setting of 1000 and a
> bgwriter_delay of 200, but we're still seeing much higher growth in the
> buffers_checkpoint than buffers_clean, with buffers_checkpoint increasing at
> about 20 times the rate that buffers_clean is. We don't see very much
> growth in the maxwritten_clean, though - something like one every couple of
> days.
>
> So the questions is, why are there still so many more checkpoint buffers
> than clean buffers written? Does the buffers_checkpoint value include more
> than we think? If not, can we tune things further?
>
> ---
> ===========================
> Samuel Nelson
> Consistent State
> www.consistentstate.com
> 303-955-0509
> ===========================
>