Hi Justin, Thank you for reviewing.
I have tried to run the below query and could see only less than 5 connections active when I get this error. The total rows I see is only 10 including idle and active sessions for this output. select pid as process_id, usename as username, datname as database_name, client_addr as client_address, application_name, backend_start, state, state_change from pg_stat_activity; Regards, Guna On Wed, May 11, 2022 at 2:15 AM Justin Pryzby <pry...@telsasoft.com> wrote: > On Wed, May 11, 2022 at 12:59:01AM +0800, Sudhir Guna wrote: > > Dear All, > > > > We have recently upgraded Postgresql 9.4 standalone server to Postgresql > > 11.2 with High Availability (2 servers : Master and Standby). > > > > While trying to test using ETL applications and reports, we observe that > > the ETL jobs fails with below error, > > > > 2022/05/06 16:27:36 - Error occurred while trying to connect to the > database > > 2022/05/06 16:27:36 - Error connecting to database: (using class > > org.postgresql.Driver) > > 2022/05/06 16:27:36 - FATAL: Sorry, too many clients already > > > > We have increased the max_connections = 1000 in postgresql.conf file. > > > > It worked ok for a day and later we get the same error message. > > > > Please help to advise on any additional settings required. The prior > > Postgresql 9.4 had the default max_connections = 100 and the applications > > worked fine. > > It sounds like at least one thing is still running, perhaps running very > slowly. > > You should monitor the number of connections to figure out what. > > If you expect to be able to run with only 100 connections, then when > connections>200, there's already over 100 connections which shouldn't > still be > there. > > You could query pg_stat_activity to determine what they're doing - trying > to > run a slow query ? Are all/most of them stuck doing the same thing ? > > You should try to provide the information here for the slow query, and for > the > rest of your environment. > > https://wiki.postgresql.org/wiki/Slow_Query_Questions > > -- > Justin >
