Paul,
I agree with the advice that batch queues would often benefit from using
oscillate, and online (C subqueue) would be best left at decay.  Many
sysadmins try to improve the performance of their batch jobs by having the
queues overlap (such as CQ=152-200, DQ=180-253), but that doesn't buy them
anything unless oscillate is turned on.  The fact that the dispatcher decays
priority based on transaction length, and that a transaction is defined as
the activity between terminal reads, and batch jobs never do terminal reads,
means that batch jobs decay to the bottom of the queue and stay there.  They
can only take advantage of the overlap during that brief time that they are
decaying.  With Oscillate, they can return to the overlapped range of
priorities occasionally.  For the same reason, using oscillate only buys you
something if your queues do overlap.

All of these questions depend on a bunch of factors, and what's right for
one shop probably won't work for others.  Keep a close eye on your system as
you experiment with these settings and be prepared to quickly change things
if your system's performance takes a nosedive.

-----Original Message-----
From: Paul Thompson [mailto:[log in to unmask]]
Sent: Friday, March 09, 2001 3:39 AM
To: [log in to unmask]
Subject: To decay or not to decay - that is the question.....


We currently have out job queues set to decay but are considering modifying
some/all to oscillate.

How have you guys out there have your queues set? Has only found any
benefits/drawbacks about making such a change? Any feedback at all would be
welcome!!

TIA

Paul Thompson
Spark Response


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