Re: jobs running in one subsystem take up more CPU then rest of jobs

["Bob P. Roche" <BRoche@xxxxxxxxxxxxxxxxx>]

Also remember the batch job is doing something it's whole run, unless it's 
waiting for a response from a remote server. The interactive job does 
something, shows the user a screen and waits for them to finish with the 
screen, then repeats that cycles. It's not always using CPU cycles. 



From:
Charles Wilt <charles.wilt@xxxxxxxxx>
To:
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Date:
11/19/2009 10:22 AM
Subject:
Re: jobs running in one subsystem take up more CPU then rest of jobs
Sent by:
<midrange-l-bounces@xxxxxxxxxxxx>



John,

If the users aren't complaining and the total CPU usage is less than
100%, then don't worry about how much the batch jobs are taking.

Look at it this way, if the CPU isn't 100%, then part of the time your
system is doing nothing....so how much did you pay for that
paperweight anyway? :)  Theoretically, you want the system to run at
95% or so all day long. Of course in real life, you've got workload
peaks & valleys, plus you want room for growth so you're not upgrading
every week.

The point is, why would you want to constrain the work being done for no 
reason?

Charles



On Thu, Nov 19, 2009 at 10:48 AM, John Allen <jallen@xxxxxxxxxxx> wrote:
> I know this question will probably have multiple answers including "it
> depends"
>
>
>
> If we have a subsystem setup to run a set of specific batch jobs. And 
these
> jobs are running at the default batch job run priority of 50
>
> (subsystem setup with normal default values you get when subsystem is
> created and the SBMJOB does not have anything but the default values
> specified)
>
>
>
> The interactive jobs are running at the default priority of 10
>
>
>
> Why do the Batch jobs (there are 5 of them total running in the 
subsystem)
> seem to be taking up to 60-70% of CPU while the interactive jobs are 
taking
> .5 - 1% each
>
> Or is this nothing to worry about, the System i will adjust resources as
> necessary to keep the interactive response time unaffected by batch 
jobs?
> I do not have users complaining about slow response times (yet) I just
> noticed this and it got me wondering why is this?
>
> And who knows if it continues they may start calling me.
>
>
>
> Also, is there something I can easily so to reduce the CPU% the batch 
jobs
> are taking?
>
> Tmeslice, or memory or anything else?
>
>
>
> Thanks
>
> John
>
>
>
>
>
>
>
>
>
> --
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