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| George Carey |
 Posted: Mon May 24, 2010 8:10 am Post subject: Client channels ... |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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Another channel question. Clients in this case.
What is the typical/most likely cause of channels to be started and apparently orphaned. I have an app server talking to MQ via Resource adapter and One channel is all that is needed but after a period of time (days), 8-10 client connections are seen connected to the MQ server from appserver. Restarting the app server container that connects with the MQ server it goes back to the one client channel connection.
The developers are not aware of any issue but I see these extra channels.
Any place to best read up on the proper behavior of client connections via a Resource Adapter. This is an Oracle app server connecting via an Oracle resource adapter.
TIA
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding")
Last edited by George Carey on Mon May 24, 2010 11:19 am; edited 1 time in total |
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| PeterPotkay |
| Posted: Mon May 24, 2010 10:45 am Post subject: Re: Client channels ... |
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Poobah
Joined: 15 May 2001
Posts: 7722
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| George Carey wrote: |
| What is the typical/most likely cause of channels to be started and apparently orphaned. |
The application has a problem and goes down a path that does not include closing the queues and disconnecting from the QM. The next ransaction establishes a new connection, which works until another problem that causes the app to end that "session" without cleaning up. Repeat until Max Active Channels is hit. Or the app recycles cleaning up all the stale connections its maintaining.
From the QM's perspective, these are not orphaned channels. They are perfectly valid connections. The app chooses not to use them.
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Peter Potkay
Keep Calm and MQ On |
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| PeterPotkay |
| Posted: Mon May 24, 2010 10:47 am Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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Or there could be a connection pool. During a burst of heavy activity the pool grows and spawns the extra connections needed, and then doesn't have any code to shrink the # back down, so the high water mark is maintained.
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Peter Potkay
Keep Calm and MQ On |
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| George Carey |
| Posted: Mon May 24, 2010 11:17 am Post subject: scenario 1 |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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Yes, the first scenario of these sounds like the more likely culprit.
This is Java code of course ... with the 'finally' method available I believe. Is there a code snippet that would close and disconnect in 99.9 of the cases from an Message server in a failsafe manner.
And is the resource adapter a possible culprit in channels staying active or not being closed as expected? I am sure the developers will say they are issuing the appropriate calls at the appropriate places.
I see the problem on occasion with Datapowers devices as well while using a very simple MPGW service to talk to MQ Servers on front and back ends.
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding") |
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| J.D |
| Posted: Mon May 24, 2010 9:01 pm Post subject: |
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Voyager
Joined: 18 Dec 2009
Posts: 92
Location: United States
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| Is there any firewall between MQ and Resource Adapter? If there is one then the firewall rule need to be defined in both ways. We had a similar problem between MQ and Tibco in the past. |
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| George Carey |
| Posted: Tue May 25, 2010 7:17 am Post subject: firewall |
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Knight
Joined: 29 Jan 2007
Posts: 500
Location: DC
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No no firewall in between.
These are internal servers on the same vlan segment.
_________________
"Truth is ... grasping the virtually unconditioned",
Bernard F. Lonergan S.J.
(from book titled "Insight" subtitled "A Study of Human Understanding") |
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