RE: Performance problems using dataqueues to NT.

[kulack@xxxxxxxxxx]

I agree.
FYI... I have no responsiblity for this code, only a little knowledge in
this area. 8-)
I did however, find problems related to this in SLIC in v4r4 for underlying
primitives that I used for my implementation of the Pthread APIs in OS/400.
The problem is that there are MI instructions that are well defined to do
this, and we're (IBM) mostly just paralyzed with fear to change things like
this sometime. (unfortunately).
I was just trying to share a few details with the group.



I was just explaining what I expected the problem was

"Do you believe that my being stronger or faster has anything
 to do with my muscles in this place?" ... "Free your mind."
Laurence Fishburne as Morpheus in 'The Matrix'.

Fred A. Kulack  -  AS/400e  Java and Java DB2 access, Jdbc, JTA, etc...
IBM in Rochester, MN  (Phone: 507.253.5982   T/L 553-5982)
mailto:kulack@us.ibm.com   Personal: mailto:kulack@bresnanlink.net
AOL Instant Messenger: Home:FKulack  Work:FKulackWrk


"Richard Jackson" <richardjackson@richardjackson.net>@midrange.com on
09/28/2000 02:31:31 PM

Please respond to JAVA400-L@midrange.com

Sent by:  owner-java400-l@midrange.com


To:   <JAVA400-L@midrange.com>
cc:
Subject:  RE: Performance problems using dataqueues to NT.



Fred:

On a RISC machine with adequate memory, it is irresponsible to use process
purge on an AS/400.  Between 1996 and 1998, purge(*yes) was the IBM/JDE
guideline for ODBC server jobs (QZDASOINIT).  In December 1998, Debbie Hatt
and Alan Wallet discovered the problem and the guideline changed.  Setting
those jobs to purge(*yes) was a very bad idea but we didn't know it at the
time.  I can speak here because it was my decision, after consultation with
the IBM ODBC database guys, to recommend that it be set that way in 1996.
I
made a mistake.  In 1998 and 1999, I spread the word to change the setting.
It took between 6 and 9 months to get the word out to everyone.

I believe that makes highly questionable any assumption on the part of IBM
developers that customers use purge.  If SLIC retains that anachronism, it
should be purged :)

Contact me offline if you want to discuss this further.  You can call
Debbie
Hatt on an inside line.

Richard Jackson
mailto:richardjackson@richardjackson.net
http://www.richardjacksonltd.com
Voice: 1 (303) 808-8058
Fax:   1 (303) 663-4325

> |-----Original Message-----
> |From: owner-java400-l@midrange.com
> |[mailto:owner-java400-l@midrange.com]On Behalf Of kulack@us.ibm.com
> |Sent: Thursday, September 28, 2000 8:23 AM
> |To: JAVA400-L@midrange.com
> |Subject: Re: Performance problems using dataqueues to NT.
> |
> |
> |
> |Many waiting primitives in the bowels OS/400 have options coded
> |in them to
> |help overall performance in the system. The optiosn tell SLIC whether a
> |wait is expected to be long > 2 seconds or short < 2 seconds.
> |This has a direct effect on how the scheduler treats the waiter, on
> |priority of the waiter, and on whether the waiter is immediately
> |paged out
> |or what. There's a significant transition that occurs in SLIC at the 2
> |second mark.
> |I suspect is related to this in some fashion.
> |
> |"Do you believe that my being stronger or faster has anything
> | to do with my muscles in this place?" ... "Free your mind."
> |Laurence Fishburne as Morpheus in 'The Matrix'.
> |
> |Fred A. Kulack  -  AS/400e  Java and Java DB2 access, Jdbc, JTA, etc...
> |IBM in Rochester, MN  (Phone: 507.253.5982   T/L 553-5982)
> |mailto:kulack@us.ibm.com   Personal: mailto:kulack@bresnanlink.net
> |AOL Instant Messenger: Home:FKulack  Work:FKulackWrk
> |
> |
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