ASG
IBM
Zystems
Cressida
Icon
Netflexity
 
  MQSeries.net
Search  Search       Tech Exchange      Education      Certifications      Library      Info Center      SupportPacs      LinkedIn  Search  Search                                                                   FAQ  FAQ   Usergroups  Usergroups
 
Register  ::  Log in Log in to check your private messages
 
RSS Feed - WebSphere MQ Support RSS Feed - Message Broker Support

MQSeries.net Forum Index » WebSphere Message Broker (ACE) Support » Is there an MRM Message Set Size limit?

Post new topic  Reply to topic
 Is there an MRM Message Set Size limit? « View previous topic :: View next topic » 
Author Message
KSkelton
PostPosted: Tue Jan 22, 2002 10:30 am    Post subject: Reply with quote

Apprentice

Joined: 28 Oct 2001
Posts: 45

MQSI 2.0.2 CSD1 +eFix67130 +IC31739
MQ 5.2 CSD1
DB2 6.1 fp8
Win NT 4.0 2@733Mhz 1GB RAM

Hi,
We are running into a problem in opening a rather large Message Set through Control Center. When we try to expand the top level Type, the CPU on the Server surges and does not return the expanded Type in time. The ConfigMgr returns a Timeout message. This also causes timeouts if anyone else tries to perform any small action to the Configmgr.

The Message Set has:

753 elements
403 String Lengths
20 Types

I do receive the following error message referring to the DB2 monitor heap:

"An entry has been logged to the DB2 Diagnostic Log
for instance DB2.
Please refer to this instance's DB2 Diagnostic Log for additional information.

2001-12-14-14.55.05.039000 Instance:DB2 Node:000
PID:274(db2syscs.exe) TID:704 Appid:none
database_monitor anchor_point::update_counter Probe:4

monitor heap exhausted"


IBM's first level of support had me increase the ConfigMgr heap size tp 2048 and the DB2 heap sizes to 1200. We also increased the JAVA Runtime which also had no effect.

IBM sent the issue on to Hursley nearly 30 days ago and they cannot get any response from them on this problem.

Any help or experiences would be appreciated.
Back to top
View user's profile Send private message Visit poster's website
mpuetz
PostPosted: Wed Jan 23, 2002 5:45 am    Post subject: Reply with quote

Centurion

Joined: 05 Jul 2001
Posts: 149
Location: IBM/Central WebSphere Services

Hi,

the dbheap setting is just one parameter in DB2
can be exhausted. Other ones which can be critical
is the apl_ctl_heap_sz of the database or mon_heap_sz,
aslheapsz and query_heap_sz of your DB2 instance.
Try increasing these values by doubling them successively or use the DB2 monitoring tools
to view your heap consumption. I'm no expert in DB2,
but a good DB2 administrator should be able to help you there.
Often also the default transaction log files are too small.
Try increasing the number of secondary log files (logsecond) for your instance.
I'm almost positive that this is a DB2 configuration problem.
So get an experienced DB2 admin involved or you may go along
with the hints I presented by trial and error.

The lesson is: Never trust default configurations for DB2.
The MQSI manuals could do much better describing the pitfalls
with DB2 and how to cure them.


_________________
Mathias Puetz

IBM-EMEA AIM Services
MQ/WMQI Specialist

[ This Message was edited by: mpuetz on 2002-01-23 15:27 ]
Back to top
View user's profile Send private message
KSkelton
PostPosted: Fri Feb 22, 2002 6:59 am    Post subject: Reply with quote

Apprentice

Joined: 28 Oct 2001
Posts: 45

Just to follow up on this problem.

The DB2 error turned out to be just a notification and a general error.
IBM and I tried tuning a number of different DB2 parms as you have mentioned.
Nothing made any difference. IBM is able to recreate the problem on a number of different builds.

The problem is MQSI cannot handle flat message structures of large size. IBM has no fix for this and did not say when they plan to enhance MQSI to support large flat structures. They simply encourage us to place a few breaks in our message sets to allow the Configmgr time to process the blocks before the CC times out.

Most message structures (e.g. COBOL copybooks) have some natural breaks like "05" levels, which automatically generate a "Type" on import. The Types provide a natural break and allows the ConfigMgr time to process the expanding of the block.

Kevin Skelton
MGIC

Back to top
View user's profile Send private message Visit poster's website
kwelch
PostPosted: Fri Feb 22, 2002 10:07 am    Post subject: Reply with quote

Master

Joined: 16 May 2001
Posts: 255

Hi Kevin,

We had the same issue about 7 months ago and we were given the same advice, add some 10 levels under the 05's to provide more breaks. At the time we were and still are using MQSI 2.0.1. We are getting ready to move to WMQI 2. I wonder if there are any improvements? Does anyone know?

Thanks,

Karen
Back to top
View user's profile Send private message Send e-mail
Tibor
PostPosted: Sun Feb 24, 2002 2:38 pm    Post subject: Reply with quote

Grand Master

Joined: 20 May 2001
Posts: 1033
Location: Hungary

Quote:

On 2002-02-22 10:07, kwelch wrote:
We had the same issue about 7 months ago and we were given the same advice, add some 10 levels under the 05's to provide more breaks. At the time we were and still are using MQSI 2.0.1. We are getting ready to move to WMQI 2. I wonder if there are any improvements? Does anyone know?

Karen,

There is a lot of improvements, but I'm not an IBM's salesman ... but my first true impression was with v2.0.2 CSD3, when MRM parser worked 5 times faster!!! And, fortunatly, WMQI v2.1 inherited this property.
Back to top
View user's profile Send private message
Tibor
PostPosted: Tue Feb 26, 2002 8:49 am    Post subject: Reply with quote

Grand Master

Joined: 20 May 2001
Posts: 1033
Location: Hungary

Quote:

On 2002-02-24 14:38, Tibor wrote:
...but my first true impression was with v2.0.2 CSD3, when MRM parser worked 5 times faster...


Sorry for mistyping - that version was v2.0.1 CSD3.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic  Reply to topic Page 1 of 1

MQSeries.net Forum Index » WebSphere Message Broker (ACE) Support » Is there an MRM Message Set Size limit?
Jump to:  



You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Protected by Anti-Spam ACP
 
 


Theme by Dustin Baccetti
Powered by phpBB © 2001, 2002 phpBB Group

Copyright © MQSeries.net. All rights reserved.