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| tanght |
 Posted: Wed Feb 23, 2011 1:18 am Post subject: multiple sender chls connected to one receiver chl |
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Novice
Joined: 04 Jan 2011
Posts: 15
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Currently we have 2 sender chls defined on 2 different servers with the same channel name, for example, AA.BB.T1
We have one receiver chl defined on QMGR BB named AA.BB.T1.
Both sender chls are in running status. and when we display the receiver chs from QMGR BB, we see that there are 2 channel status and there are 2 different sequence numbers.
Initially I thought sequence number was tagged to the channel names only, but from this example it seems that it is not.
Has anyone ever experienced this kind of setup? and what is the sequence number tagged to? both the channel name and the connection ip?
I really appreciate if someone can help me on this issue..
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| exerk |
| Posted: Wed Feb 23, 2011 2:41 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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This is not a good thing to do, two SDRs to one RCVR, because if one of the remote queue manager initiates a message flood there's only one way to stop it at your end, and that will also affect the 'good' remote queue manager.
As regards how the sequence number is tagged, I'm not sure if it's in a scratchpad somewhere but I'm sure a passing knowledgeable person will be along in a minute...
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| Vitor |
| Posted: Wed Feb 23, 2011 5:30 am Post subject: Re: multiple sender chls connected to one receiver chl |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| tanght wrote: |
| Has anyone ever experienced this kind of setup? and what is the sequence number tagged to? both the channel name and the connection ip? |
The receiver MCA maintains the sequence number for each sender MCA conversation it's having.
I've seen this done a few times, usually as a sort of "poor man's cluster" so when queue manager C wants to talk to queue manager B just like queue manager A already does then all you need to do is define a sender channel called B with the correct parameters and you're off.
As my most worthy associate points out, this is not an optimal design, or a design where you at least need to understand the weaknesses. The receiver MCA is both a choke point and a single point of failure. If the message flood mentioned happens, then all WMQ traffic into the box has to be stopped. If the flood is less serious, you'll see traffic degredation and find your ability to tune this inhibited. You certainly won't be able to apply Quality of Service to one queue manager and not the other. If the receiver MCA crashes, you're likewise hosed.
And if someone or something resets one of the sender channels so the sequence number goes back to 1 (or any specific number) you can't reset that particular conversation but have to reset all the channels. With 2 boxes, not too much of a pain. If your site grows, it will be a major pain.
(Well not for me - I crossed my arms, said "I told you this was a risk" and made the manager who told me it was a very implausible scenario find someone else.)
You asked the time and I've told you how to build a watch. Apologies.
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Honesty is the best policy.
Insanity is the best defence. |
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| gbaddeley |
| Posted: Wed Feb 23, 2011 2:40 pm Post subject: Re: multiple sender chls connected to one receiver chl |
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Jedi
Joined: 25 Mar 2003
Posts: 2498
Location: Melbourne, Australia
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| tanght wrote: |
....Initially I thought sequence number was tagged to the channel names only, but from this example it seems that it is not.
Has anyone ever experienced this kind of setup? and what is the sequence number tagged to? both the channel name and the connection ip? |
The message sequence number is "tagged" to the channel name and the ip address, using messages in the SYSTEM.CHANNEL.SYNCQ that are managed by the MCAs. That's why migrating a remote qmgr to a new system with a different ip address will result in channel sequence errors.
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Glenn |
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| someonesumit |
| Posted: Wed Feb 23, 2011 11:51 pm Post subject: |
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Novice
Joined: 18 Sep 2009
Posts: 16
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Hi,
The seq number is basically between sender channel and receiver channel.
if you have two sender channels in two queue managers(QM1 & QM2) with same name pointing to same remote queue manager(QM3) suppose.
Channel names are CHIN.CHOUT in both the queue managers QM1 and QM2, and there is only one receiver channel CHIN.CHOUT in QM3.
If you start the channel in both the sending end queue manager and start sending the data, there will be two instances of receiver channel will run in receiving end with name CHIN.CHOUT and both receiver channel will maintain their respective sequence number. On point here to notice is that both instances of receiver channel will have different remote queue manager name and MCA job name.
So the conclusion is that the seq number is mainly maintained by sender end channel and MCA agent. |
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| bruce2359 |
| Posted: Thu Feb 24, 2011 5:47 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9405
Location: US: west coast, almost. Otherwise, enroute.
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| someonesumit wrote: |
Hi,
...
Channel names are CHIN.CHOUT in both the queue managers QM1 and QM2, and there is only one receiver channel CHIN.CHOUT in QM3. |
Are your qmgrs on WMQ for z/OS?
| Quote: |
| On[e] point here to notice is that both instances of receiver channel will have different remote queue manager name |
Different how? Do you mean QMIDs will be different?
Different how? If this is z/OS (just guessing due to the use of CHIN.), the jobname can be any name that is valid for MVS. WMQ imposes no restrictions or requirements.
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Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
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| tanght |
| Posted: Thu Feb 24, 2011 10:24 pm Post subject: |
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Novice
Joined: 04 Jan 2011
Posts: 15
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First I would like to thanks for all the reply, I really appreciate it.
In my environment the receiver is in z/os and the sender is in windows.
The naming convention in our system is that "AA.BB.T1" means that AA is the sender qmgr name and BB is the receiver chl name. Thus the 2 different server is having the same qmgr name defined on both servers.
when we display the channel status on the receiver end, both channel shows the same RQMNAME and MCA Id is also the same as it is tagged to the receiver chl.
I agree with Victor that it is poor design and they should go to cluster setup. This is single point of failure for receiver end and also it is difficult to reset sequence number at the receiver end.
But anyway this was already live in production environment thus I also can not do much about it. |
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| exerk |
| Posted: Fri Feb 25, 2011 12:59 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| tanght wrote: |
| ...the 2 different server is having the same qmgr name defined on both servers... |
Please tell me that you do not mean that the queue managers on each platform are named exactly the same, e.g. QM1P on z/OS and QM1P on Windows?
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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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| Vitor |
| Posted: Fri Feb 25, 2011 6:20 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| exerk wrote: |
| tanght wrote: |
| ...the 2 different server is having the same qmgr name defined on both servers... |
Please tell me that you do not mean that the queue managers on each platform are named exactly the same, e.g. QM1P on z/OS and QM1P on Windows? |
And if it is, going to a cluster setup will be fatal. Identically named queue managers in the same cluster works as well as warming up your bath water by taking an electric heater in with you...
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Honesty is the best policy.
Insanity is the best defence. |
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| bruce2359 |
| Posted: Fri Feb 25, 2011 6:48 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9405
Location: US: west coast, almost. Otherwise, enroute.
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| Quote: |
| when we display the channel status on the receiver end, both channel shows the same RQMNAME and MCA Id is also the same as it is tagged to the receiver chl. |
Please post an example of the receiver channel tagged to/with the MCA Id.
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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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