My Application has normally 25 to 30 connections and it is doing lot of insert/update/delete operation.
The database size is 100GB.
iowait is at 40% to 45 % and CPU idle time is at 45% to 50%
TOTAL RAM = 8 GB TOTAL CPU = 4
postgresql.conf parametre:
autovacuum = off
That could be the source of your problem. Why autovacuum is turned off? Has database grown from 5GB to 100GB because of bloat or so much new data has been inserted? If it's a bloat, vacuum may not now be enough to recover from that and you would need a vacuum full. In general, it's not a good idea to turn autovacuum off.