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Application Performance Improvement Tips

 
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kart__0987

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Joined: 18 Jul 2006
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PostPosted: Thu Dec 16, 2010 12:47 pm    Post subject: Application Performance Improvement Tips
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Hi All,
I have been asked to come up with a strategy to improve the Performance of a bunch of Mainframe applications at my site. We have identified a few focus areas as mentioned Below. Could you please suggest additional areas of opportunity as well as Best Practices and tips that will be of help in this process.

1. Long running batch Jobs - Identify the reasons for High CPU consumption using Strobe etc.. and take corrective action
2. High CPU online transactions
3. Reduce Batch Window by optimizing Job schedule
4. Eliminate Redundant processes and Jobs
5. Optimize DASD and TAPE storage by modifying JCL, reduce GDG limit etc.
6. Optimize SQL queries
7. Tips for better cobol Coding

Appreciate your thoughts and inputs.
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Robert Sample

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Joined: 06 Jun 2008
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PostPosted: Thu Dec 16, 2010 6:35 pm    Post subject:
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DB2 indexes and access paths can yield nice improvements

Better COBOL coding will not, in most cases, yield enough benefit to pay for the changes -- modern processors run so fast that the program has to be doing a lot (as in BILLIONS) of COBOL statements for any improvements to be noticeable.

Reducing the batch window can backfire -- a production system WILL have problems every now and then, and the shorter batch window increases the chances that online systems will not come up on time.

Optimizing DASD and tape won't improve performance and can increase run times if taken too far.
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Phrzby Phil

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PostPosted: Thu Dec 16, 2010 10:39 pm    Post subject:
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How does GDG limit affect performance?
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kart__0987

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PostPosted: Thu Dec 16, 2010 10:45 pm    Post subject:
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one of the areas we are looking at is to reduce DASD and other storage costs. Keeping GDG limit at minimum and eliminating unneccessary backups will help towards that.
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Robert Sample

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PostPosted: Thu Dec 16, 2010 10:53 pm    Post subject:
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Reducing DASD and other storage costs has absolutely nothing to do with performance improvement -- especially since storage (and other) costs can be very highly dependent upon the site chargeback policies.

Perhaps you need to step back and rethink just what you are wanting help with?
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kart__0987

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PostPosted: Thu Dec 16, 2010 11:06 pm    Post subject:
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Apologize for not making it clear.It is a Performance improvement/Technology cost saving excercise. At this time i'm looking for ideas that can help acheive that.we will then prioritize the ones that involve least optimization effort and provide maximum benefit.
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enrico-sorichetti

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PostPosted: Thu Dec 16, 2010 11:09 pm    Post subject: Reply to: Application Performance Improvement Tips
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for these kind of services/exercises the current consulting rates very easily exceed 2000€ per day icon_biggrin.gif
( plus expenses, naturally )
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Fri Dec 17, 2010 12:09 am    Post subject:
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Hello,

Quote:
Appreciate your thoughts and inputs.


Probably not what you are looking for, but. . .

The laundry list posted has no specifics - no actual goals. This list may be what impresses some non-technical manager, but doesn't have any working points. The direction of "we want to make things better" is a motherhood statement - nothing can be said against wanting to make things better.

If your interest is tuning some of the things you have, some analysis needs to be done identifying specifics that are not acceptable (i.e. it runs too long and/or requires too many resources and/or . . .).

How is excessive cpu usage determined? Any other resource?

Suggest (and this has already been mentioned) that you not reduce the size of the batch window. . . "Things to do" tend to grow rather than shrink.

Depending on exactly what is happening on the system, it may be time to consider cpu/dasd upgrades.
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enrico-sorichetti

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PostPosted: Fri Dec 17, 2010 12:53 am    Post subject: Reply to: Application Performance Improvement Tips
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in the starting list the only thing that makes sense is
4) Eliminate Redundant processes ....
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Bill O'Boyle

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Joined: 14 Jan 2008
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Location: Atlanta, Georgia, USA

PostPosted: Fri Dec 17, 2010 12:58 am    Post subject: Reply to: Application Performance Improvement Tips
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Don Leahy recently posted a link for COBOL performance tips, which might also be helpful -

http://ibmmainframes.com/viewtopic.php?p=257132&highlight=#257132

Bill
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Phrzby Phil

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PostPosted: Fri Dec 17, 2010 7:53 am    Post subject:
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Motherhood with or sans apple pie?
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dick scherrer

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PostPosted: Fri Dec 17, 2010 10:34 pm    Post subject: Reply to: Application Performance Improvement Tips
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Yes icon_wink.gif

And baseball, oh my. . .
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