ca.portal.admin

Limits and Statistics

Discussion created by ca.portal.admin on Jun 19, 2008
Hello Listers,
At our site we are looking at ways to reduce the CPU usage of the IDMS
CV's. I remember seeing some statistics stating that having statistics
collection on added approximately 8 - 10% CPU overhead. Also, turning on
LIMITS increased the CPU usage roughly 7%. I have found some internal
documentation that states this, but I cannot find any 'official' CA
documentation that does.=20

Does anyone else on the list remember seeing similar statements about
the CPU overhead of LIMITS & STATS?

The reason for the question is that I ran some tests on one of our CV's.
Using a testing tool we ran almost 70,000 tasks thru the CV with LIMITS
enabled and STATISTICS collection on. We then shutdown the CV and
recorded the # of tasks, CPU used, etc. Next we changed the SYSGEN to
set LIMITS disabled and STATISTICS off. We also changed the #PMOPT macro
to stop writing SMF data. We reran the exact same set of scripts. The
results showed only a 2% reduction in CPU usage.

Does this figure surprise anyone else? Any ideas what I could be missing
to only see this small reduction?

Thanks for any help you can give.

Dan Hall
GE Capital Solutions
Database Administrator

T 513.217.5060
E dan.hall@ge.com
www.ge.com/capitalsolutions/

Middletown, OH 45042
General Electric Capital Corporation
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Re: Limits and Statistics
"Dan,

If you're using ADSO, you can reduce CPU by removing retrieval locks wher=
e they're not needed. If you have dialogs that are used allot during the =
day, are mostly retrieval and do only a small amount of updating, you can=
put the updating functions in a mapless dialog, do a 'LINK NOSAVE' from =
the retrieval dialog to the update dialog, have the update dialog re-esta=
blish currency and turn retrieval locks off in the retrieval only dialogs=
. If a dialog is retrieval only and does not pass currencies to an update=
dialog, the retrieval locks should be turned off. This could save allot =
of CPU and also reduce deadlocking depending on how the dialogs are coded=
and the number of transactions they process.

Margaret

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