Err, sorry, I think I meant bgwriter_lru_maxpages, not lru_max_dirty.
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Samuel Nelson
Consistent State
www.consistentstate.com
303-955-0509
===========================On Tue, Feb 22, 2011 at 3:42 PM, Sam Nelson
<samn@consistentstate.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?
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===========================
Samuel Nelson
Consistent State
www.consistentstate.com
303-955-0509
===========================
