any comments on MQ queue sharing. ----- Forwarded by Geok Hoon FOO/ISD/HDB/SG on 05/11/2002 02:04 PM -----
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Michael F
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<mmurphy@MQSOLUTIO Subject: Re: Why MQ Cluster or MQ List
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Please respond to
MQSeries List
You are comparing MQ Cluster and MQ List? Do you mean distribution list?
Clustering and distribution lists are not related. A distribution list
puts the same message to more than one queue. In a cluster you only put
one message to one queue. In a cluster you can have a queue on more than
one queue manager by the same name within a cluster. When you do a put, it
will only put the message to one of the queues in the cluster. When you
open the cluster queue, it will either open one of them in the cluster and
put all messages with that object handle to one queue, or it can put the
message to all queues in a round-robin fashion, depending on the option
chosen in your open options.
Now that's out of the way.
The main advantage to clustering is job security because it can be very
high maintenance. So if you need to create work for yourself, add
clustering. Not everyone has had a bad experience with clustering, but I
think everyone will agree it is sometimes difficult to maintain and
troubleshoot. With every release, IBM says clustering was bad in the
previous release but now it is better. I have not had the chance to test
it in 5.3 yet though. Clustering gives you a cheap way to balance your
workload across queue managers (probably across machines) so you can scale
your application. I say it is the cheap way because it is not balanced, it
is round-robin. If you have a complex network with many to many
connections, clustering can reduce the number of channel definitions. This
is because it creates channels as needed automagically. I have used
clustering for this purpose before. If a queue manager becomes
unavailable, it routes all messages to the remaining available queue
managers. This is cheap availability but not good for HA because messages
will get stuck on the failed queue manager. Also, it doesn't react to the
queue manager's availability very well and sometimes messages get stuck.
You should carefully evaluate if clustering is right for your architecture.
Do not use it just because it is cool or because some IT director thinks it
will solve all your problems. The main advantages are:
- Spread workload across queue managers
- Provides a cheap, but unreliable psuedo-failover solution
- An application can easily put a message on a queue on another queue
manager without altering the queue manager
- Can be more or less administration depending on your luck
What about distribution lists? They are good if you want to send the same
message to many queues on many queue managers. With this, you can put the
message once rather than 20 times. It is a useful feature. If you need to
send the same message to many places also consider pub/sub if that meets
your needs.
Mike Murphy
Sr. Middleware Consultant
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http://www.mqsolutions.com
Office: 562-902-7800
Cell: 602-741-6689
Idamar Ferreira <[EMAIL PROTECTED]> wrote:
Date 11/04/2002 11:49:39 AM
Recieved:
To: [EMAIL PROTECTED]
cc:
Bcc
Subject: Why MQ Cluster or MQ
List
Hi all,
Does someone know what I take advantage using a MQ Cluster?
Why do I have to use MQ Cluster?
Would I consider use MQ List?
Please don't consider the beneficts for administration.
TIA
Idamar Ferreira
Especialista - GEROP - CAIXA
mailto:idamar.ferreira@;caixa.gov.br
((61)414-4935
"Take care of your People, They are the unique unrecoverable piece of your
business"
.
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