On Mon, Apr 21, 2008 at 5:50 AM, Adrian Moisey <[EMAIL PROTECTED]> wrote: > Hi > > # ps -ef | grep idle | wc -l > 87 > # ps -ef | grep SELECT | wc -l > 5 > > > I have 2 web servers which connect to PGPool which connects to our postgres > db. I have noticed that idle connections seem to take up CPU and RAM > (according to top). Could this in any way cause things to slow down?
Something is not quite with your assumptions. On an unloaded server, open a bunch of connections (like 500) from psql doing nothing, and cpu load will stay at zero. IOW, an 'idle' connection does not consume any measurable CPU resources once connected. It does consume some ram but that would presumably at least partly swap out eventually. What's probably going on here is your connections are not really idle. Top by default aggregates usage every three seconds and ps is more of a snapshot. During the top a single connection might accept and dispose 0, 1, 50, 100, or 1000 queries depending on various factors. Your sampling methods are simply not accurate enough. With statement level logging on (with pid on the log line), you can break out and measure query activity by connection. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
