Re:Re: concurrent users

Discussion created by ca.portal.admin on Apr 14, 2008
Hi Wayne:

You're likely to get answers all over the board on this one, but perhaps
that is exactly what you want.

Other than some obvious restraints, like virtual memory,
network bandwidth, CPU cycles, etc., I have never heard of an
IDMS system that could not support the maximum concurrent
number of users (albeit I had a lot of fun during the Cullinet
years doing performance and tuning consulting to achieve
exactly that result ;-}} ).

That said, I suspect you may be asking about life in the 'new
world', with web services, etc.

I have personally simulated 10K users hitting an ASP page that
connected/retrieved minimum data from an IDMS database. I
don't have all of the details anymore, but the overall response
was about 1.17 seconds running the simulation for about 15
minutes. This was done on CA iron in
2003/2004 on a R14.1 CV.

Of course, it was just a simulation, but it illustrates that
you can push a rather large load through a CV if you have
enough back-end resources.
Again, just my 2cents...your results WILL vary...

Please feel free to contact me offline (

Tom Schoenborn
TA Schoenborn & Associates LLC

----- Original Message -----
From: ""Doneker, John W (US SSA)"" <John.Doneker@BAESYSTEMS.COM>
Sent: Monday, April 14, 2008 2:48 PM
Subject: concurrent users

Does anyone have an idea of the concurrent number of users IDMS
can handle?

J. Wayne Doneker

BAE Systems

York Pa.,

717 225 8109
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Re: concurrent users
"Yes, I think you are correct. Depends on the line that these pterms are
defined under. For VTAM and UCF, I believe you are totally right. But,
I've seen sysgens with tons of pterms/lterms, unfortunately they were
not used by the application programs. In a VTAM line setup, you can
define multiple VTAM lines, and then a max number of pterms under it. I
am not familiar with the specifics of the 32k limit, whether the
dictionary can't handle anymore of the pterm record type, or the line
definition can't handle any more then 32k. I would guess it's the line
that can't have more then 32k pterms hanging off it, and in that case, I
would just define more lines. Of course each line is tied to an applid,
and this could get complicated VTAMwise.

Lutz Petzold
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