From: Justin Pryzby <pryzby@telsasoft.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: dangal <danielito.gallo@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: pg_stat_bgwriter
Date: Mon, 14 Oct 2019 17:16:02 -0500
Message-ID: <20191014221602.GL3599@telsasoft.com> (raw)
In-Reply-To: <20191014181847.6lf5s3fwuh7ui25r@development>
References: <1571016455698-0.post@n3.nabble.com>
<20191014181847.6lf5s3fwuh7ui25r@development>
On Mon, Oct 14, 2019 at 08:18:47PM +0200, Tomas Vondra wrote:
> Note: FWIW, a single snapshot of pg_stats* may be misleading, because
> it's cumulative, so it's not clear how accurately it reflects current
> state. Next time take two snapshots and subtract them.
For bonus points, capture it with timestamp and make RRD graphs.
I took me awhile to get around to following this advice, but now I have 12+
months of history at 5 minute granularity across all our customers, and I've
used my own implementation to track down inefficient queries being run
periodically from cron, and notice other radical changes in writes/reads
I recall seeing that the pgCluu project does this.
http://pgcluu.darold.net/
Justin
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To: pgsql-performance@postgresql.org
Cc: pryzby@telsasoft.com, tomas.vondra@2ndquadrant.com, danielito.gallo@gmail.com
Subject: Re: pg_stat_bgwriter
In-Reply-To: <20191014221602.GL3599@telsasoft.com>
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