On Sun, May 29, 2022 at 01:20:12PM +0000, James Pang (chaolpan) wrote: > We have a performance test on Postgresql 13.4 on RHEL8.4 , just after connection storm in ( 952 new connections coming in 1 minute), a lot of backends start on " D " state, and when more sessions got disconnected, they do not exit successfully, instead became "defunct". No errors from postgresql.log , just after the connection storm, some pg_cron workers can not started either. The server is a Virtual machine and no IO hang (actually) IO load is very low. Could be a postgresql bug or an OS abnormal behavior? What settings have you set ? https://wiki.postgresql.org/wiki/Server_Configuration What extensions do you have loaded? \dx Send the output of SELECT * FROM pg_stat_activity either as an attachment or in \x mode? What is your data dir ? Is it on the VM's root filesystem or something else ? Show the output of "mount". Are there any kernel messages in /var/log/messages or `dmesg` ? How many relations are in your schema ? Are you using temp tables ? Long-running transactions ? -- Justin
