On Mon, May 14, 2012 at 8:58 PM, Daryl Stultz <daryl.stultz@xxxxxxxxxxxxx> wrote: > Hello, > > I have a tomcat server with 7 applications connecting to PG 8.4. All apps > use connection pooling. Over the weekend the apps ran out of connections. > The max connections is at the default of 100 which is more than enough for > normal operations. In attempting to resolve the situation I shutdown tomcat > only to find that PG still appeared to have connections out. So if a Looks like the problem is on apps side from the first glance. Try to do select client_addr, client_port from pg_stat_activity; after shutting down the Tomcat and find out what holds the <client_port> on the <client_addr> [user@<client_addr> ~]$ sudo netstat -pnao | grep <client_port> The second column from the right will be the process pid. Also I would suggest to update PG to the latest version before making further investigation, if it is possible of course. > connection is between A and B, the A side (tomcat) was shut down, but the B > side still thinks it's connected. I had to restart PG to get the connections > to clean up. > > I've had a similar situation happen where the database server was severely > overloaded. Many long-running queries were started. The application > connection pools closed the connections after they had been out too long (60 > seconds). Eventually things caught up where CPU usage of the database server > returned to normal but there remained several backends that did not appear > to be connected anymore (a "select from pg_stat_activity" query in > combination with "top" showed this). The situation this weekend does not > appear to have been triggered by a heavy load. > > My question is this: how is it possible for PG to get into a state where it > thinks it is connected to an application but the application doesn't agree? > (Since I was unable to connect due to max clients reached, I was not able to > kill the backends using psql). I'm looking for any avenue that I might > explore. > > Thanks. > > -- > Daryl Stultz > _____________________________________ > 6 Degrees Software and Consulting, Inc. > http://www.6degrees.com > http://www.opentempo.com > mailto:daryl.stultz@xxxxxxxxxxxxx -- Sergey Konoplev a database and software architect http://www.linkedin.com/in/grayhemp Jabber: gray.ru@xxxxxxxxx Skype: gray-hemp Phone: +79160686204 -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
