MVSFORUMS.com

[manu]

There is a Cobol batch job which takes around 500 CPU mins in production and in test region it tooks only 300 mins. The job has a tape input file with about 400 million records and it filters the records based on the criteria in a set of other input files. All the processing is with in Cobol internal tables and data is all in files with minimal DB2. With the same code and same input files the job took 200 CPU mins more in production and I am not really sure why. The output files matches perfectly.The only other difference I see is the EXCP count between prod and test which is more in prod by 2000K. The prod and test DB has the same data and there is very minimal DB2 in this job. Any idea on why there is a big CPU mins difference between prod and TEST? If it is due to different processor etc. I would think PROD should be more faster. Please let me know if you have any comments /guesses or tips.Thank you for your inputs.

[kolusu]

[haatvedt]

If you have the Strobe tool from Compuware or a similar tool from another vendor I would suggest that you use that to analyze the performance.

Are any of the files in your job VSAM ? If so I would look carefully at the VSAM buffering as it can make a very significant impact on both the EXCP counts (I/O) and also the cpu time. Strobe will do a very good job of showing information about the dataset characteristics and also the I/O counts.

If you are using VSAM and SMB (system managed buffering), then perhaps that is something to look at as well. The default buffering could be different in prod and test.

Since the output is matching, I suspect that the dataset characteristics are different between prod and test. I would look at blocksize as Kolusu suggests and also the buffering.

If you have Strobe and can generate a text report, perhaps you could post the #DSC (dataset characteristics) and #LSR (local shared resources) secions. Also the #PSU (program summary usage) would be useful as well.
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Chuck Haatvedt

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[manu]

Thanks for your inputs. Will check and update.