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| jhidalgo |
 Posted: Wed Jun 10, 2009 1:05 pm Post subject: Failover using qmgr alias |
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Disciple
Joined: 26 Mar 2008
Posts: 161
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Hi all,
I want to implement failover qmgrs. The idea is to have one qmgr for each box, with the same name as the server itself, and then create the failover which will be the "default qmgr" with a remote queue with the name of the main qmgr and pointing to the failover. Something like this:
Server name: florida1
Name of the qmgr: florida1
in that same box, the failover qmgr: floridabk1 as the default qmgr with one remote queue named: florida1 pointing to florida1bk.
So if the main qmgr(florida1) fails I just start florida1bk and the all the applications in that server will reconnect to the bk qmgr.
Is this a good idea ?, can this work with applications using binding(not mq client) ??
thanks. |
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| PeterPotkay |
| Posted: Wed Jun 10, 2009 5:40 pm Post subject: Re: Failover using qmgr alias |
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Poobah
Joined: 15 May 2001
Posts: 7722
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| jhidalgo wrote: |
So if the main qmgr(florida1) fails I just start florida1bk and the all the applications in that server will reconnect to the bk qmgr.
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Why do you think florida1bk will start if something caused florida1 to go down?
If florida1bk would come up at that point, why wouldn't florida1 if you tried it instead?
| jhidalgo wrote: |
| Is this a good idea? |
Not in my opinion.
_________________
Peter Potkay
Keep Calm and MQ On |
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| Vitor |
| Posted: Wed Jun 10, 2009 11:21 pm Post subject: Re: Failover using qmgr alias |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| PeterPotkay wrote: |
| jhidalgo wrote: |
| Is this a good idea? |
Not in my opinion. |
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| Vitor |
| Posted: Wed Jun 10, 2009 11:22 pm Post subject: Re: Failover using qmgr alias |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| jhidalgo wrote: |
| So if the main qmgr(florida1) fails I just start florida1bk and the all the applications in that server will reconnect to the bk qmgr. |
And all the messages sitting unprocessed on the first queue manager just sit there.
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| jhidalgo |
| Posted: Thu Jun 11, 2009 6:27 am Post subject: Re: Failover using qmgr alias |
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Disciple
Joined: 26 Mar 2008
Posts: 161
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| PeterPotkay wrote: |
Why do you think florida1bk will start if something caused florida1 to go down?
If florida1bk would come up at that point, why wouldn't florida1 if you tried it instead?
Not in my opinion. |
florida1bk will not start by itself, it should be a manual process.
florida1 may have a problem like: missing journal files, the MaxChannels was too short or you simply need to apply a change that requires a restart for the qmgr, so you apply it to the bk and then to the main qmgr. |
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| Vitor |
| Posted: Thu Jun 11, 2009 6:36 am Post subject: Re: Failover using qmgr alias |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| jhidalgo wrote: |
| florida1bk will not start by itself, it should be a manual process. |
And messages will still be stuck on the downed main server
| jhidalgo wrote: |
| florida1 may have a problem like: missing journal files |
Queue managers do not have journal files they have log files. These should not just "go missing" unless the file system is corrupted. In which the point about a 2nd queue manager on the same server not starting either applies.
| jhidalgo wrote: |
| the MaxChannels was too short or you simply need to apply a change that requires a restart for the qmgr |
Both of these are far more simply dealt with by a 10 minute maintenance window at the end of the business day.
Another issue is that you describe your solution as "failover" queue managers. If the server does go down, and the site management say:
| Quote: |
| The florida1 queue manager is down and it's impacting us. Switch to the failover floridabk1 at once! |
what will be your response? Have you underlined to the relevant people that this isn't "failover" in the "business continuity, distaster recovery" sense in which the word is normally bandied about?
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Insanity is the best defence. |
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| jhidalgo |
| Posted: Thu Jun 11, 2009 2:37 pm Post subject: Re: Failover using qmgr alias |
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Disciple
Joined: 26 Mar 2008
Posts: 161
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| Vitor wrote: |
And messages will still be stuck on the downed main server
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Yes, totally right on this one
| Vitor wrote: |
Queue managers do not have journal files they have log files.
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In i5 each qmgr has journal files, and these sometimes give problems, sometimes you have to reconstruct the journals and it takes some time, a lot more than starting a qmgr.
| Vitor wrote: |
Both of these are far more simply dealt with by a 10 minute maintenance window at the end of the business day.
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I'm planning for the incidents, not planned jobs |
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| Vitor |
| Posted: Thu Jun 11, 2009 11:51 pm Post subject: Re: Failover using qmgr alias |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| jhidalgo wrote: |
| In i5 each qmgr has journal files, and these sometimes give problems, sometimes you have to reconstruct the journals and it takes some time, a lot more than starting a qmgr. |
Apologies - you didn't mention platform & I assumed distributed.
| jhidalgo wrote: |
| Vitor wrote: |
Both of these are far more simply dealt with by a 10 minute maintenance window at the end of the business day.
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I'm planning for the incidents, not planned jobs |
I was confused by your use of the phrase "need to apply a change". In my world changes are planned.
But to sumarise - your original post asked "do you think this is a good idea?"; my answer remains "no I don't".
But no-one's asking me to like it, or implement it. There is also a realistic chance I'm wrong. You know your situation and if you believe this is the best way for you even given the comments made, then.....
 
and may you never have a situation that requires it's use! 
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| jhidalgo |
| Posted: Fri Jun 12, 2009 7:26 am Post subject: |
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Disciple
Joined: 26 Mar 2008
Posts: 161
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thanks a lot vitor, your inputs are very important for me, that's why I post ! 
I am trying to find a way to reduce the downtime for the services I support, we have iSeries and windows applications, but since CCDT doesn't exists for iSeries (with old RPG apps) we are looking(unsuccessfully) for ways to circumvent this limitation, so my question can be rephrased as:
If one qmgr fails, or one parameter that requires a restart needs to be changed immediatly, what can I do ?, is it possible to do something anyway (  ) ?
I thought that qmgr aliases would have helped me, but seems like I am looking for something not possible 
thanks anyway |
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| exerk |
| Posted: Fri Jun 12, 2009 7:32 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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You can use a queue manager alias as the RQMNAME, and have that alias defined in each of your receiving queue managers; you will also need a generically named RCVR channel in each receiving queue manager. If whichever one you're using goes down, you can have the originator stop their SDR, alter the CONNAME, and restart. Of course, this solution still does not address the issue of any messages stranded on the downed queue manager.
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| PeterPotkay |
| Posted: Fri Jun 12, 2009 9:23 am Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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| exerk wrote: |
| Of course, this solution still does not address the issue of any messages stranded on the downed queue manager. |
Or the issue that local apps wil have trying to connect in bindings mode to the down QM.
_________________
Peter Potkay
Keep Calm and MQ On |
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| exerk |
| Posted: Fri Jun 12, 2009 10:20 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| PeterPotkay wrote: |
| exerk wrote: |
| Of course, this solution still does not address the issue of any messages stranded on the downed queue manager. |
Or the issue that local apps wil have trying to connect in bindings mode to the down QM. |
Granted. I was looking at it narrow focus, only from the 'originator' aspect.
_________________
It's puzzling, I don't think I've ever seen anything quite like this before...and it's hard to soar like an eagle when you're surrounded by turkeys. |
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