On Wed, Aug 24, 2011 at 9:33 AM, Greg Smith
<greg@2ndquadrant.com> wrote:
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.
I suppose you could use tcpdump on a separate system with a mirrored switch port and have it log TCP SYN and FIN packets on port 5432 to your database server only. Keeps all I/O off your database server.
tcpdump -w port5423.log -n "tcp and port 5432 and tcp[tcpflags] & (tcp-syn|tcp-fin) != 0 and host IP"
HTH.
Greg