we have a pooling on the application level. however we never had this issues before this start happning since last couple of days in past we had over 2300 sessions but no issues.
yes it is older however we do apply security patches now a then.
redhat doesn't really support mixing packages from different releases, they only test things with all packages from the same snapshot. "yum update" should bring the whole system up to current.
regarding max connection its the application design however it does not have that many active session. postgres=# select count(*) from pg_stat_activity; count ------- 1818
so there were 1818 postgres client processes at the time it coudln't create a new process. thats certainly a larger number than I've ever run. if I have client software that has lots and lots of idle connections, I use a connection pooler like pgbouncer, in transaction mode.
