Re: Is there some way to limit Batch CPW ?

Vengoal,

You might just need more interactive cpw.

Instead of phrasing as batch cpw vs interactive cpw, simplify as batch jobs
vs interactive jobs.  How do you prevent batch jobs from hindering the
performance of your interactive jobs.

Big batch jobs like query affect interactive two ways: they read a lot of
pages of disk data into memory; flushing out the non database pages of the
interactive jobs.  They queue up the io request channel with their large
buffered sequential io requests.

Priority on the system only applies to cpu. Not disk io. So when your
interactive user presses the enter key there is a lag while the interactive
jobs memory pages which had been paged out because of the batch job are
paged back in. Then when the interactive job does disk io there is a lag
because the system is still filling up the query jobs large buffers.

One answer is to make sure batch runs in a separate memory pool from
interactive.  Keeping the batch memory pool very small during times of heavy
interactive work can theoretically limit the look ahead io of the batch
jobs.

That all said, with 35 cpw you might just have cfint running too much as you
hit your interactive cpw limit. Use the WrkSysAct command to see if cfint is
running.

hth,

Steve Richter

----- Original Message -----
From: "Vengoal Chang" <vengoal@ddsc.com.tw>
To: <midrange-l@midrange.com>
Cc: <tsc@tw.ibm.com>; <sputer@ddsc.com.tw>; <simon@ddsc.com.tw>;
<laurence@ddsc.com.tw>; <brianwan@ddsc.com.tw>; <benson@ddsc.com.tw>
Sent: Friday, May 17, 2002 4:01 AM
Subject: Is there some way to limit Batch CPW ?


Dear Sir,
For example, one AS/400 with 35/600 CPW. The interactive job CPW 35 is
limited by interactive feature card. So the Batch job will not inflected by
Interactive job.  But when many batch jobs run large query function will
result the interactive job performance dowing when the batch CPW greater
than 565(600-35). Is there any ways to limit the Batch CPW up to 565 or some
feature to set the interactive and batch without influenced each other ?
Does IBM consider this ?


Best Regards,

Vengoal Chang
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