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Message
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| skailash |
 Posted: Mon Apr 25, 2011 11:22 am Post subject: Configuring MQ listener in Veritas HA |
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Newbie
Joined: 11 Apr 2011
Posts: 6
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Hello,
We are using MQ 7.0.1 and in the process of implementing Veritas HA. I am trying to setup the monitoring for listener. Currently, the listener has been defined to be under the control of queue manager such that it will start automatically with the queue manager.
Mq question - With setting up the monitoring agent in Veritas, will the listener be started separately and so, should I define the control of listener as Manual in the queue manager?
Here is the sample listener configuration as mentioned in the MQ HA Veritas agent document.
Application was4WSMQ_listen
(
User = mqm
StartProgram = "/opt/mqm/bin/runmqlsr -t tcp
-i 1.2.3.4 -m venus.veritas &"
StopProgram = "/opt/mqm/bin/endmqlsr -m venus.veritas"
MonitorProcesses = {"/opt/mqm/bin/runmqlsr -t tcp
-i 1.2.3.4 -m venus.veritas" }
)
Thanks
Sam |
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| Vitor |
| Posted: Mon Apr 25, 2011 11:32 am Post subject: Re: Configuring MQ listener in Veritas HA |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| skailash wrote: |
| Mq question - With setting up the monitoring agent in Veritas, will the listener be started separately and so, should I define the control of listener as Manual in the queue manager? |
It depends. Who do you plan to handle the various failure scenarios in Veritas? Under what circumstances would you handle a listener failure differently to a queue manager failure?
This will determine how you control the listener.
| skailash wrote: |
| Here is the sample listener configuration as mentioned in the MQ HA Veritas agent document |
You might also want to mention which document you mean.
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| skailash |
| Posted: Mon Apr 25, 2011 12:04 pm Post subject: Configuring MQ listener in Veritas HA |
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Newbie
Joined: 11 Apr 2011
Posts: 6
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Veritas agent for WMQ will handle the failure scenarios and page the system admin in the event of fault. It seems to me that there is a potential for the listener to go down and stop listening while the queue manager is still up and running. So we want to make sure that we capture that and fail over to the other node through Veritas. But I want to make sure that there is no conflict during startup such that the queue manager automatically started the listener when it came up and then the MQ agent also tried to bring it up afterwards and it goes into a loop.
I am referring to "Veritas High Availability Agent for WebSphere MQ Installation and Configuration Guide". |
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| Vitor |
| Posted: Mon Apr 25, 2011 12:40 pm Post subject: Re: Configuring MQ listener in Veritas HA |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| skailash wrote: |
| Veritas agent for WMQ will handle the failure scenarios and page the system admin in the event of fault. It seems to me that there is a potential for the listener to go down and stop listening while the queue manager is still up and running. So we want to make sure that we capture that and fail over to the other node through Veritas. But I want to make sure that there is no conflict during startup such that the queue manager automatically started the listener when it came up and then the MQ agent also tried to bring it up afterwards and it goes into a loop. |
I know the agent does the work, but it handles the scenario how you've determined it should & configured it to do.
So if that's the way you want it done that's what you should do.
| skailash wrote: |
| I am referring to "Veritas High Availability Agent for WebSphere MQ Installation and Configuration Guide". |
And you couldn't manage to post a link? 
Having got Mr Google to show me the document, the script you posted (page 39 on the PDF I found) describes it as "an example script" and refers you to the IBM documentation. So if you want to use that example then do so & go in peace. If you don't, don't.
As I said, it depends how you want to handle things.
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| exerk |
| Posted: Mon Apr 25, 2011 2:15 pm Post subject: Re: Configuring MQ listener in Veritas HA |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| skailash wrote: |
| ...It seems to me that there is a potential for the listener to go down and stop listening while the queue manager is still up and running... |
There is always the possibility that a process may fail.
| skailash wrote: |
| So we want to make sure that we capture that and fail over to the other node through Veritas. |
Why? Why not attempt a restart of the Listener? Why fail over without at lease attempting a number of restarts? It's quicker for one thing.
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| fjb_saper |
| Posted: Mon Apr 25, 2011 7:17 pm Post subject: Re: Configuring MQ listener in Veritas HA |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| exerk wrote: |
| skailash wrote: |
| ...It seems to me that there is a potential for the listener to go down and stop listening while the queue manager is still up and running... |
There is always the possibility that a process may fail.
| skailash wrote: |
| So we want to make sure that we capture that and fail over to the other node through Veritas. |
Why? Why not attempt a restart of the Listener? Why fail over without at lease attempting a number of restarts? It's quicker for one thing. |
And what of the case when you purposefully need to do maintenance and want the listener to be down? 
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MQ & Broker admin
Last edited by fjb_saper on Tue Apr 26, 2011 12:46 pm; edited 1 time in total |
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| Vitor |
| Posted: Tue Apr 26, 2011 4:12 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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I support and endorse the comments of my associates.
Especially fjb_saper who correctly extends my comment regarding "how you want to handle things" to include non-emergency things. 
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| SAFraser |
| Posted: Mon May 02, 2011 1:39 pm Post subject: |
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Shaman
Joined: 22 Oct 2003
Posts: 742
Location: Austin, Texas, USA
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The Veritas HA MQ agent monitors a number of MQ processes. The listener is one of them. If you have developed your own agent, then you can designate the critical processes that, if failed, will trigger a failover. Failure of the listener is one of several processes that will cause VCS to failover the queue manager.
We put the listener under the control of the queue manager (as well as the command server, etc). During failover, VCS simply starts the queue manager on the standby node.
We do not allow restart attempts of the listener process because our older clients do not have reconnect logic. If the listener fails, human intervention is required no matter where it restarts.
For maintenance events, the VCS service group is "frozen". Freeze/unfreeze can be accomplished via the Veritas GUI or via command line (hagrp). VCS will continue to monitor resources (thereby continuing to record and alert on failures) but will not instantiate a failover.
You cannot freeze only the listener; you must freeze the entire service group. But that's okay, really, because while you are doing maintenance, you are quite focused on the system anyway.
Good luck. Test, test, test-- that's our advice! The whole process was much trickier than we anticipated. And if you do not have root privileges, insist on read access to the VRTSvcs/logs folder. Become familiar with the MQ log and the engine log. |
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