Message-ID: <4E5519C2.7030607@2ndQuadrant.com>
Date: Wed, 24 Aug 2011 11:33:22 -0400
From: Greg Smith <greg@2ndQuadrant.com>
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To: pgsql-performance@postgresql.org
Subject: Re: How to track number of connections and hosts to Postgres cluster
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On 08/24/2011 07:07 AM, Venkat Balaji wrote:
> But, if put log_connections to on and log_disconnections to on 
> wouldn't the Postgres be logging in lot of data ?
> Will this not be IO intensive ? I understand that this is the best 
> way, but, would want to know if there is an other way to reduce IO ( 
> may be through queries to catalog tables ).
>

Your requirements include:  " I need all the host IPs making a 
connection to Postgres Cluster (even for a fraction of second)."

The only way to do this is to log every connection.  Any other approach 
for grabbing the data, such as looking at pg_stat_activity, will 
sometimes miss one.

If you're willing to lose a connection sometimes, a cron job that polls 
pg_stat_activity and saves a summary of what it finds will normally use 
less resources.  But connections that start and end between runs will be 
missed.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us