z/OS Monitoring
After providing a very simple and very fast performance monitoring solution that provided full system and job analysis, zOSMON new supports CICS using the SMF 110 record.
The primary objective of zOSMON is to provide full performance management at extremely low overhead. Including CICS in this suite met the same objective. Installations processing 100 transactions per second may not even notice any increase in the zVPS processing requirements.
Sample zview tabs on our system will show by
region
and by
transaction
Velocity Software on all platforms has supported a one minute reporting interval for operational alerts and ease of performance analysis. In z/OS, there are the RMF interval setting, and a CICS interval setting for providing statistics and for providing details on inflight transactions. Analysis of CICS response time, second by second shows very degraded CICS response time during the second of statistics gathering. Thus every 60 seconds, response time will take a hit for one second (or less). This was measured in an LPAR with two virtual CPUs. The performance degradation will likely be less with a faster CPU, which can be monitored by installations with ZOSMON. Historically installations have used 15 minutes to reduce the amount of data and this processing degradation. The following was repeatable at the top of every minute with one minute CICS interval:
Trans Resp Disp SUSP CPU Time sysid Count Time Time Time Time -------- ----- ----- ----- ----- ----- ----- 18:18:55 VSI1 32 0.019 0.013 0.006 0.010 18:18:56 VSI1 40 0.033 0.024 0.008 0.014 18:18:57 VSI1 24 0.017 0.014 0.003 0.011 18:18:58 VSI1 32 0.032 0.028 0.004 0.019 18:18:59 VSI1 30 0.034 0.021 0.013 0.015 18:19:00 VSI1 40 0.269 0.054 0.215 0.012 <---- 18:19:01 VSI1 40 0.014 0.007 0.008 0.004 18:19:02 VSI1 64 0.006 0.004 0.002 0.004 18:19:03 VSI1 40 0.005 0.004 0.002 0.003 18:19:04 VSI1 16 0.002 0.002 0.001 0.002As a repeatable measurement, it would be worth repeating this analysis on larger and faster systems.
Note that the same analysis was done with RMF intervals at 1 minute and 15 minute, and very little impact on CICS transactions could be detected.