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Anil George
New User
Joined: 13 Feb 2008
Posts: 7
Location: India
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When doing the performance comparison of two jobs which are the parameters to be compared?
We have the parameters like
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EXCP CPU SRB CLOCK SERV PG PAGE SWAP VIO SWAPS STEPNO
281 .00 .00 .00 9802 0 0 0 0 0 1
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I am aware that the main parameters to be compared are TOTAL CPU TIME and TOTAL ELAPSED TIME. I searched for the same in google but was quite unable to find the definition of some of the parameters except
EXCP: The number of EXCPs (Execute Channel Program) performed during the measurement interval.
SRB: The number of CPU seconds consumed in SRB mode during the measurement interval. This does not include any SRB time consumed by the Application Performance Analyzer measurement task.
SERV: CPU SERV + I/O SERV + OTH SERV
Can somebody please let me know what these parameters actually mean?
Thanks for stopping by...
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Bill Dennis
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Joined: 17 Aug 2007
Posts: 562
Location: Iowa, USA
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EXCP is an indication of disk and tape I/O activity.
SRB is CPU time consumed on behalf of your job by system-level routines. The biggest variation I've seen comes with I/O activity. Run a program with small file blksizes and again with large file blksizes and notice the reduction in SRB time. SRB + TCB = total CPU
SERV represents Service Units, an attempt to standardize job resource usage on different sized processors. Faster CPUs have a higher SU/sec rating so a program that takes less CPU time on a fast processor will show about the same service units consumed as the slower processor. |
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Anil George
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Joined: 13 Feb 2008
Posts: 7
Location: India
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Thanks Bill for the reply....
I was comparing two jobs with some DB2 performance improvements and was curious to know which are the parameters to be compared other than the total elapased time and cpu time.
Ideally which parameters should be considered for measuring/comparing the perfomance of programs.
Rgds,
Anil |
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Bill Dennis
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Joined: 17 Aug 2007
Posts: 562
Location: Iowa, USA
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| CPU (including SRB) and EXCP are the main values to compare. For DB2 jobs, there may be time accounted for in the DB2 tasks for your job so I'm not sure how to accurately compare performance of two DB2 jobs. |
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