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| gurusridhar |
 Posted: Tue Dec 02, 2003 12:36 am Post subject: Any example for load balance and failover |
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Newbie
Joined: 19 Nov 2003
Posts: 9
Location: Singapore
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hi,
Any example for load balance and failover in Java for MQ. |
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| GreatG |
| Posted: Tue Dec 02, 2003 1:00 am Post subject: |
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Novice
Joined: 02 Dec 2003
Posts: 13
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Mean Sample code in Java,
check manual Using Java for WebSphereMQ |
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| dtauzell |
| Posted: Wed Dec 17, 2008 11:38 am Post subject: |
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Apprentice
Joined: 23 May 2002
Posts: 37
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I don't have code to give you, but what I did for JBOss/MQ was:
1. Have a way to notify a JMX bean that MQ seems dead
2. JMX bean then removes all JNDI entries for MQ and creates new ones for
a different Queue Manager. |
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| Vitor |
| Posted: Thu Dec 18, 2008 1:00 am Post subject: Re: Any example for load balance and failover |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| gurusridhar wrote: |
| Any example for load balance and failover in Java for MQ. |
Load balancing in WMQ should be done with a cluster. Your application should have no involvement in this (aside from not specifying a specific target).
Failover should be done with HA software (server side) or a client connection table (client side). Again this should not involve your application.
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| zpat |
| Posted: Thu Dec 18, 2008 1:04 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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Depends.
I like the MQ client model with multiple threads (and/or multiple servers) accessing the same queues.
Automatic load-balancing and failover with zero effort and no clustering needed. |
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| George Carey |
| Posted: Thu Dec 18, 2008 2:28 pm Post subject: automatic load balancing |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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I agree think I like the client model better as well ... but where/how does one get the 'automatic' no effort load balancing. Automatic failover I can see with Client Channel tables configured appropriately but "auto" load balancing ?
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding") |
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| fjb_saper |
| Posted: Thu Dec 18, 2008 11:04 pm Post subject: Re: automatic load balancing |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| George Carey wrote: |
| I agree think I like the client model better as well ... but where/how does one get the 'automatic' no effort load balancing. Automatic failover I can see with Client Channel tables configured appropriately but "auto" load balancing ? |
George, auto load balancing on the chl table is a feature from V7. You won't find it on V6. 
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| George Carey |
| Posted: Fri Dec 19, 2008 11:53 am Post subject: V7 |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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| Quote: |
| auto load balancing on the chl table is a feature from V7. You won't find it on V6 |
Ahh ... I vaguely remember reading something about it ... obviously I'm not using V7 to any extent yet !!!
Well this in another reason to get to it ! ... Thank you for reminder FJ.
Regards,
GTC
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding") |
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| zpat |
| Posted: Fri Dec 19, 2008 1:04 pm Post subject: Re: automatic load balancing |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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| George Carey wrote: |
| I agree think I like the client model better as well ... but where/how does one get the 'automatic' no effort load balancing. Automatic failover I can see with Client Channel tables configured appropriately but "auto" load balancing ? |
Simple.
Host the queues on a single queue manager (hardware clustered if you like for resilence).
Host the applications on two or more app servers, using client connections to the queue manager (just the one QM).
Long running (listener style) client apps will pull messages as fast as they can process then (but not faster!).
If one app server fails - the other carries on (anything in flight is rolled by using syncpoint).
No orphaned messages to worry about.
Remember - don't trigger - just use MQGET with WAIT and process the message before getting the next one. Use SYNCPOINT to protect against application failure. |
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| George Carey |
| Posted: Fri Dec 19, 2008 2:29 pm Post subject: two side of load balancing |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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Well that is the other end of load balancing I guess. I was thinking more on the distribution of the messages in-bound ... and FJ answered that .. RT?M but yours addresses the other side (application processing) load balancing ... a different and useful approach as well.
Your comment about processing the message before doing the next get ... I am assuming you mean to leave the syncpoint uncommitted until processing is completed so that a failure will/would cause a roll back. I will have to read up on JMS to see how that is accomplished in the API ... I don't suppose there is a method as simple as saying MQcommit ... actually I think its session.commit or something like that but that is using JTA if I recall, and then there is container managed bean environment frufru ... yada yada ....
Sorry my growing disdain for 'esoterical software conceptualization and jargonism' is showing. I need to open a pub ... much more sane.
GTC
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding") |
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| fjb_saper |
| Posted: Fri Dec 19, 2008 2:38 pm Post subject: Re: two side of load balancing |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| George Carey wrote: |
Well that is the other end of load balancing I guess. I was thinking more on the distribution of the messages in-bound ... and FJ answered that .. RT?M but yours addresses the other side (application processing) load balancing ... a different and useful approach as well.
Your comment about processing the message before doing the next get ... I am assuming you mean to leave the syncpoint uncommitted until processing is completed so that a failure will/would cause a roll back. I will have to read up on JMS to see how that is accomplished in the API ... I don't suppose there is a method as simple as saying MQcommit ... actually I think its session.commit or something like that but that is using JTA if I recall, and then there is container managed bean environment frufru ... yada yada ....
Sorry my growing disdain for 'esoterical software conceptualization and jargonism' is showing. I need to open a pub ... much more sane.
GTC |
George you memory serves you well.
You do have transaction processing rolled into the session with JMS.
In stand alone processing make sure you mark the session as transacted and you issue the session.commit().
In server processing most of this is handled by the deployment descriptor, and container managed.
The odd case has bean managed transactions... Those are always to look at in a case by case basis, often suspend the global transaction, if it exists, and absolutely need to resume it before giving back control (need for a finally block).
Have fun.
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| zpat |
| Posted: Sat Dec 20, 2008 3:00 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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| JMS uses syncpoint automatically on transacted sessions. |
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