Re: Performance Issues on 570

Nelson,
When migrating to our 570, we noticed a big difference in programs that 
used open query files.  The programs were not choosing the same 
index/access path as on v5r2.  Unfortunately, IBM in all of their wisdom 
does not capture index builds for open query files in the database 
monitor.  So we had to put our jobs in debug to find an access path 
suggestion.  Once we built the access path, one job when from 1 hour 22 
minutes to 22 seconds. 

Hope this helps.

Andy

Andrew Goade
Hub Group Inc.
3050 Highland Parkway, Suite 100 
Downers Grove, IL 60515 
Email:  agoade@xxxxxxxxxxxx
Office: (630)795-2352
Fax:     (630)271-3647



Nelson Smith <ncsmith@xxxxxxxxxxxxxxx> 
Sent by: midrange-l-bounces@xxxxxxxxxxxx
08/11/2005 07:46 PM
Please respond to
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>


To
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
cc

Subject
Re: Performance Issues on 570






About a month ago, my company upgraded from an 870 to a 570.  We went 
from 48G to 96G and more than doubled our disk capacity and increased 
the number of arms from around 90 to 128. We went down in processors 
from 12 to 11. Unfortunately, we also upgraded from V5R2 to V5R3 at the 
same time (I know, I know). 

After spending many hundreds of thousands of dollars, the sad result is 
that some of our major batch processes have more than doubled in run 
times.  For example, a 4-hour nightly billing run is now taking upwards 
of 9 hours.  Needless to say, there is much knashing of teeth going on 
around here and it is not a pleasant experience. It seems to be 
primarily a batch problem.  Processor efficiency and interactive 
response times seem to be improved.  During the batch runs, there seems 
to be a great amount of paging going on.

Both the old system and the new one, have (had) a development partitian 
and a production partition. Relative sizes have not changed.  There have 
been no significant changes in database sizes or the applications. Both 
Business Partner and IBM have had many engineers working on the problem 
for a month now and of course, everyone is pointing fingers at everyone 
else.  They have been running every sort of performance management tool 
you can think of. They have tuned this and that. They have replace card 
after card.  They have tried all sorts of caching schemes.  All to no 
avail.

Lately, they are starting to point fingers at the applications.  Now I 
grant you that our applications are old and could stand much 
improvement, but they have not changed since before the upgrade.  We are 
embarking on a modernation project in development, but we will not 
implement any such improvements until the upgrade issues are settled.

The one question I have not been able to get a straight answer out of 
any of these engineers, and the reason for this post, is what has been 
the experience of other recent converts to the 570?  Or, what has been 
the experience of other upgraders from V5R2 to V5R3? Particularly in 
relation to long-running batch jobs.  I can't think of anything unique 
in what we are running.  We have very little, if any, embedded SQL. 
That's the only thing I've seen any complaints about on this list.  Has 
anyone else going to a 570 experienced any sort of major slowdown?  At 
this point, we are willing to look at anything.