RE: Auto Tuning

[Chris Bipes <chris.bipes@xxxxxxxxxxxxxxx>]

Ok it is time for me to chime in regarding time slice.   99% of the time
your job will need resources not in memory in normal business applications.
They are data intensive and unless you have enough memory to load all your
data into, you will need to page the requested records from storage to
memory.  This is a long wait event and your job will give up its activity
level.  Now if you are running complex calculations or your program is stuck
in a loop, lower time slice will keep you from bringing the system to its
knees.  In this scenario you will hit your time slice limit and give up the
processor.  Depending on configuration, you may even be moved to a different
memory pool.  I am running my 820 with a time slice of 100 and could
probably go lower.  We did not adjust after moving from a 720 to an 820.
Since I have made the change, a broken program has not kill performance to
the point of taking minutes to change screens like we had with the time
slice of 2,000.

Chris Bipes

-----Original Message-----
From: trevor perry

Nathan,

It seems you have confused terms here.
Paging is not "a useless activity". If you need database records, they must
be paged into memory. How is that a useless activity?

Adjusting the timeslices down has meant that time spent on wasted timeslice
activity (yes, it happens) has been reduced and the system performs better.
Autotuning is not to make similar classes of jobs have equity, but ALL jobs
across the system be treated according to the prescribed authorities.