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| DumbDumb |
 Posted: Thu Mar 03, 2011 3:42 am Post subject: MQ Clustering Configuration |
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Newbie
Joined: 03 Mar 2011
Posts: 3
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Hi,
Very little experience with MQ and on very tight budget. When I say we have a tight budget I pretty much mean we have no budget so redundant servers unfortunately aren't an option for us at the moment.
Want High Availability. By this I mean on the one AS400 and one Windows server. If one of the servers goes down then we are in a whole other spot of bother!
New project.
Quote Engine on Windows 2003 server. AS400 Database on other server.
Quote Engine to make requests to AS400 for data which is then returned.
AS400 to make requests to Quote Engine for data which is then returned.
I was looking into clustered managers in case a non network issue took down one of the managers for some reason we would want subsequent messages to process like normal until someone got a chance to investigate the issues with the failed manager.
As some requests will be coming from the internet we want to have more than one QM on the AS400 in case one QM goes down, we don't want internet users left hanging so we want second QM to kick in. I'd imagine we are looking at clustering on the AS400.
On the Windows 2003 server we will have a similar set up. Do we have two clusters? One on each server. Or are the four QM in the one cluster?
If the QM on both servers are not in the one cluster we would have to use one Gateway MQ to connect into the clusters. However if this Gateway QM goes down all connections are lost?
What are our options? If you need further details let me know. Any help would be greatly appreciated.
Regards,
DumbDumb |
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| zpat |
| Posted: Thu Mar 03, 2011 3:55 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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Having two QMs on one server does not really give much more resilience than having one QM (imho).
What is picking up the messages? How is this application started and can you run two copies of it? |
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| exerk |
| Posted: Thu Mar 03, 2011 4:17 am Post subject: Re: MQ Clustering Configuration |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| DumbDumb wrote: |
| ...Want High Availability. By this I mean on the one AS400 and one Windows server. If one of the servers goes down then we are in a whole other spot of bother!... |
So your people want a Rolls-Royce solution but only want to pay for a Trabant?
The only way you will get HA is to pay for it and for Windows that means Microsoft Cluster Server (MSCS) or Multi-Instance (MI) queue managers which can only be instituted on Domain Controllers (I am assuming you're at WMQ V7.0.1 because if not then MSCS is your only option). iSeries can also be set up for MI queue managers (at WMQ V7.0.1) but I'm completely blank about how HA was done for that platform previously.
_________________
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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| DumbDumb |
| Posted: Thu Mar 03, 2011 4:31 am Post subject: |
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Newbie
Joined: 03 Mar 2011
Posts: 3
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On each side (AS400 and Windows) we have a polling program that polls the queue(s) for a new message.
MQGET picks up the message from the queue and if the polling program is happy it passes it on for processing.
There is one instance of this application per queue. One message is processed at a time. Once it has been processed the polling program takes in the next message.
Are we wasting our time looking into clustering? Would it not be better to have 2 QM even if they are on one server, one as a failover in case one goes down? |
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| zpat |
| Posted: Thu Mar 03, 2011 4:38 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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You can run two (or more) copies of the polling program against the same queue. This gives very effective load balancing since each program will only pull as fast as it can process the messages. Also messages will not be left orphaned if one program fails.
Personally I would not bother with clustering. Websphere MQ does not fall over by itself and anything which affected one QM is going to affect the other one. The only reason I would have two in a cluster is if you hoped to later get more servers. The cost of another server is minimal (on windows) surely?
You could even put the QM on the AS/400, which is a very reliable system. That way you host all the middleware together. |
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| exerk |
| Posted: Thu Mar 03, 2011 4:59 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| DumbDumb wrote: |
| ...Would it not be better to have 2 QM even if they are on one server, one as a failover in case one goes down? |
As has been pointed out many times before on this site, queue manager clustering is a load-balancing option not fail-over. Any messages on the 'dead' queue manager will be stranded until such time as the queue manager can be successfully restarted.
_________________
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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| DumbDumb |
| Posted: Thu Mar 03, 2011 5:26 am Post subject: |
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Newbie
Joined: 03 Mar 2011
Posts: 3
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Thanks all...
One thing... a Trabant.... Little bit up market. If we said we could invoke a wheel barrow to get the messages delivered and it was free I think the idea would be used! If anyone does have a wheelbarrow lying around contact wheelbarrowsolution@dumbdumb.com
I don't THINK we will be looking at more servers but who knows what will happen down the line. We might find a bit of cash money under a rock or something.
Many thanks for your help. It is something to report back anyway. I could be back with some more basic questions yet. So be warned! |
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| mqjeff |
| Posted: Thu Mar 03, 2011 6:34 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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The only response to someone asking you to BIG thing for ZERO dollars is to tell them you've done everything that can be done.
If they quibble, remind them that no matter what else, they are still paying for your time. So you can not do *anything* for ZERO dollars.
If they then say "well, that's overhead money it's not real money"... then ask them what other "overhead" money is available.
And then go look for another job. |
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| bruce2359 |
| Posted: Thu Mar 03, 2011 7:09 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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| Quote: |
| Want High Availability |
You will need to discuss with your management what High Availability (HA) means in real, practical terms. Your boss may have read the letters 'HA,' and said "Wow, we want that," without understanding what it means.
There is a significant difference between HA and continuous operation - having more than one queue available to receive messages - which is what WMQ clusters offer.
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
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| Mitra |
| Posted: Mon Mar 21, 2011 9:56 am Post subject: |
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Voyager
Joined: 21 Mar 2011
Posts: 78
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| bruce2359 wrote: |
| Quote: |
| Want High Availability |
You will need to discuss with your management what High Availability (HA) means in real, practical terms. Your boss may have read the letters 'HA,' and said "Wow, we want that," without understanding what it means.
There is a significant difference between HA and continuous operation - having more than one queue available to receive messages - which is what WMQ clusters offer. |
Hi i had the similar problem too |
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| bruce2359 |
| Posted: Mon Mar 21, 2011 10:11 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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Welcome to the ever-longer "HA misunderstood" list. 
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
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