High CPU Usage after Activating Detector & SSA

Products

• Detector for DB2 for z/OS

Issue/Introduction

Noticing high CPU usage/overhead after activating Detector and SSA for 4 members

of the 5-Way DB2 Datasharing Group on 05/26/2021 at 07:00am EST.

 

 

 

Environment

Release : 20.0

Component : CA Detector for DB2 for z/OS

Resolution

Having reviewed the Xmanager dumps and PDT/PSA Datastores.
It is noted that the PSA sampling rate is set to 50%. 
It is recommend lowering the sampling rate to 3% 
for all Subsystem Analyzer collections. 
This will significantly reduce the combined Detector 
and Subsystem Analyzer CPU overhead. 

Recommended Sampling Rate
Getpages Per Object Expected
3 percent
300,000 or more
6 percent
150,000 or more
12 percent
70,000 or more
25 percent
30,000 or more
50 percent
10,000 or more
100 percent (sampling not enabled)
0 (no minimum)