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| swatkats |
 Posted: Tue May 25, 2010 5:04 pm Post subject: Max Channel Count keeps on increasing |
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Novice
Joined: 22 May 2010
Posts: 22
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The situation is that when the application team starts their application and connect to the queue manager the max count of the server connection channel reaches its max limit within seconds. I understand that this problem has a fix in V7 by limiting the number of connections that can be with a sever Conn channel.
MQ version :Name: WebSphere MQ
Version: 6.0.2.1
Application connecting : WPS
Anyone faced/facing same problem!?
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| mvic |
| Posted: Tue May 25, 2010 5:18 pm Post subject: Re: Max Channel Count keeps on increasing |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| swatkats wrote: |
The situation is that when the application team starts their application and connect to the queue manager the max count of the server connection channel reaches its max limit within seconds. I understand that this problem has a fix in V7 by limiting the number of connections that can be with a sever Conn channel.
MQ version :Name: WebSphere MQ
Version: 6.0.2.1 |
- What is the max limit set to?
- How many clients are connecting in to the queue manager?
- Why are you running such a very old level of MQ code?
- It's not necessarily a problem, so does not necessarily have a fix. Except that your architects might not have anticipated the number of concurrent clients you are seeing. That would be a problem. One to talk to the architects about.
As for v7, there is the capacity to multiplex client-server channels together from the same client process to the same qmgr. Not sure if that's the v7 optimisation you're referring to. "Sharing conversations" is the terminology in the MQ information center.
Hope this helps. |
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| swatkats |
| Posted: Tue May 25, 2010 5:34 pm Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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| Quote: |
| What is the max limit set to? |
Server is AIX and it is set to 100
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| How many clients are connecting in to the queue manager? |
Single WPS client connecting to the server connection channel, so i am suspecting that it needs a fix there but not sure if that can be the only problem here.
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| Why are you running such a very old level of MQ code? |
it is still under support till 2011 
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| It's not necessarily a problem, so does not necessarily have a fix. Except that your architects might not have anticipated the number of concurrent clients you are seeing. That would be a problem. One to talk to the architects about. |
Makes sense very much, since all others are simple java clients as far as i know and this is being the only WPS client may be the case. But again am not sure why this could happen only in the case of WPS? 
| Quote: |
| As for v7, there is the capacity to multiplex client-server channels together from the same client process to the same qmgr. Not sure if that's the v7 optimisation you're referring to. "Sharing conversations" is the terminology in the MQ information center |
Yes adding to this terminology i am referring to channel limits and channel instance limits |
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| Vitor |
| Posted: Tue May 25, 2010 8:32 pm Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| swatkats wrote: |
| Quote: |
| Why are you running such a very old level of MQ code? |
it is still under support till 2011 |
Not the point my most worthy associate is making I believe. WMQv6.0.2.1 is a very old level. There have been many fixes applied in newer version since then and we (or at least he and I) wonder why you're not making use of them.
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| swatkats |
| Posted: Tue May 25, 2010 8:51 pm Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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| Quote: |
| WMQv6.0.2.1 is a very old level. |
No doubts I agree on this point that it is very old. So can it be avoided if we go for the latest maintenance level fix pack? I am not sure. |
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| mvic |
| Posted: Wed May 26, 2010 1:50 am Post subject: |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| swatkats wrote: |
| Single WPS client connecting to the server connection channel, so i am suspecting that it needs a fix there but not sure if that can be the only problem here. |
If only one client connects, it cannot break through a limit that's set at 100. I think you will need to investigate what those 100 connections really are, and where they are coming from. Use DISPLAY CONN and DISPLAY CHSTATUS on the qmgr to help you do that.
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| Makes sense very much, since all others are simple java clients as far as i know and this is being the only WPS client may be the case. But again am not sure why this could happen only in the case of WPS? |
Now I'm confused. You said there is only one client connecting. Please clarify: the question again: "How many clients are connecting in to the queue manager?"
Hope this helps |
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| mvic |
| Posted: Wed May 26, 2010 1:56 am Post subject: |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| swatkats wrote: |
| Quote: |
| WMQv6.0.2.1 is a very old level. |
No doubts I agree on this point that it is very old. So can it be avoided if we go for the latest maintenance level fix pack? I am not sure. |
Read through http://www.ibm.com/support/docview.wss?rs=171&uid=swg27007069 for a list of bugs that have been fixed since 6.0.2.1.
Your problem sounds more like it will be fixed by an architectural decision to reduce the number of clients, or raise the server-side limit, or something like that. Not a fix in the queue manger.
However the arguments for staying up to date with fix packs is more general than this. It is useful to remind oneself (by reading that page above) of what fixes are missing from your installation. |
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| swatkats |
| Posted: Wed May 26, 2010 2:02 am Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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the client say that they use 5 connection factories ( on WPS )whose max connection has been set to 10 for each connection factories (Haven't worked on WPS). I assume that the connection(threads) are not getting properly released and they are trying more connection before completely releasing the existing thread connected. So i suspect that it is some setting on their side is screwing things up. I hope i am making a point clear here 
Some times even bouncing the channel is not helping much since they connection (from the same IP) increase to the max value within seconds if their application is connected.  |
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| mvic |
| Posted: Wed May 26, 2010 2:09 am Post subject: |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| swatkats wrote: |
| I assume that the connection(threads) are not getting properly released and they are trying more connection before completely releasing the existing thread connected. So i suspect that it is some setting on their side is screwing things up. I hope i am making a point clear here |
I am clear what you are saying, so it would be interesting to hear what you learn from the architects and your WPS admins about this. Do the architects need to specify bigger limits on the qmgr, or do the WPS guys need to fix a bug (or a misconfiguration..)?
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| Some times even bouncing the channel is not helping much since they connection (from the same IP) increase to the max value within seconds if their application is connected. |
Are you talking about stopping the SVRCONN on the qmgr side? I'm not sure what problem that would solve. |
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| fjb_saper |
| Posted: Wed May 26, 2010 2:09 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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So with 5 CFs @ max 10 connections you should see a max of 50 connections from that source. If you have already more than 50 other connections (connections from a different source) you may be over the default 100 and need to raise the server limit.
Have fun 
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MQ & Broker admin |
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| swatkats |
| Posted: Wed May 26, 2010 2:17 am Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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Do the architects need to specify bigger limits on the qmgr, or do the WPS guys need to fix a bug (or a misconfiguration..)?
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Yes they are raising a PMR for this will share the update.
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| Are you talking about stopping the SVRCONN on the qmgr side? I'm not sure what problem that would solve |
yes i am referring to the SVRCONN channel.  When the count say reaches a maximum of 90 we bounce the channel and it reduces the connections that are hung at times. hope this helps.
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| So with 5 CFs @ max 10 connections you should see a max of 50 connections from that source. If you have already more than 50 other connections (connections from a different source) you may be over the default 100 and need to raise the server limit. |
No the queue manager is only for that application and i ve seen all the connections comes from the same IP. |
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| swatkats |
| Posted: Wed May 26, 2010 2:18 am Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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| To be more clear WPS application is going for PMR. |
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| SAFraser |
| Posted: Wed May 26, 2010 2:05 pm Post subject: |
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Shaman
Joined: 22 Oct 2003
Posts: 742
Location: Austin, Texas, USA
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Do all 50 connections represent an IPPROC on the queues? (i.e., Are they all doing GETs?)
When listeners are configured in WAS, we see one IPPROC into the queue immediately (to browse) and a second IPPROC when a message is processed. Each one initiates a svrconn channel.
Have you considered increasing the MaxChannels to a much higher number, and then see if the connections at some point stop increasing?
Maybe nothing is broken. Just an idea. |
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| swatkats |
| Posted: Wed May 26, 2010 10:03 pm Post subject: |
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Novice
Joined: 22 May 2010
Posts: 22
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Ok.. I checked for the qstatus with IPPROCS more than 25 i could see only some broker queues being accessed not the application queues this happened when the connection count with the SVRCONN was at 85 wondering why they always leave orphaned connections which helps neither of us
Ok .. my understanding is if there are orphaned processes on a SVRCONN channel when you stop the channel with mode force they should be removed and when you start them up the connection should be clean. But i dont know why they immediately shoot up the connection to 90 or 80 even after they claim that their max count for each of their 5 connection factory is 10 (note that only these 5 connection factories use this channel). May be the PMR they raised will help us. |
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| mvic |
| Posted: Thu May 27, 2010 1:52 am Post subject: |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| swatkats wrote: |
| Ok .. my understanding is if there are orphaned processes on a SVRCONN channel when you stop the channel with mode force they should be removed and when you start them up the connection should be clean. |
When you stop the SVRCONN, doesn't that break all clients connected to it? I imagine it would. Doesn't that make a bad situation worse?
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| But i dont know why they immediately shoot up the connection to 90 or 80 even after they claim that their max count for each of their 5 connection factory is 10 (note that only these 5 connection factories use this channel). |
Try to find out what those connections are actually doing. Not merely that they are connections. Use DISPLAY CONN.
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| May be the PMR they raised will help us. |
Hope so. |
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