There is a situation in which the Oracle DB server (Oracle 10.2.0.4.0 - 64bit ;Non-RAC; SUSE Linux 10 sp2 ia64) becomes very slow at some intervals. Users get slow response. Even logging into the machine is slow. After 15-45 minutes it becomes OK.
- There are no particular sessions that are causing the load
- sar -q command shows that the average load at that time is > 70 for a 12 CPU machine. idle time is 0%
At what point one can conclude that it is CPU starvation and hence AWR Oracle wait times are getting inflated because of CPU starvation? using Oracle wait times as per AWR to tune the instance has not helped so far. The application is a third party package that is running for many years satisfactorily. We can not change the SQLs.
A general guideline or your experiences will be helpful.