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| Vitor |
 Posted: Thu Nov 29, 2007 4:10 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| niraj.chaudhary wrote: |
One more thing, isn't SVRCONN initiated by MQ client? if it is so, then it should be MQ client, who should be closing it?
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MQClient isn't a discrete piece of software, it's a series of libraries allowing a client connection to be established by an application. You'll find the same principles in use for database clients on DB2 & Oracle where you're using SQL against a database not running on your local machine.
In each case, there are rules about client connections that naturally vary from software to software. The general principle is "you opened it, you close it". There's no difference (to the server) between a connection that has no data flowing down it because the application has disconnected and a connection that has no data flowing down it because the application is doing something else at the moment. There can be ways to mitigate or housekeep such situations but they're generally non-optimal because the only definitive source of information on the need for the connection is the app that needed it in the first place!
The solution that MQ uses is to impose a limit on connections (as you've discovered). The broad design rational is that once you've hit the resource limit for connections it's better to refuse new ones than close ones that "look" unused to make more room.
Before our more experienced posters jump on me let me repeat that's the broad principle - I know that behaviour on the ground is more subtle than that!
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Last edited by Vitor on Thu Nov 29, 2007 4:14 am; edited 1 time in total |
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| jefflowrey |
| Posted: Thu Nov 29, 2007 4:11 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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You probably need more connections than you think you do, for a JMS App Server MDB - about two or three per instance of the MDB.
So you may just need to get your MQ Admin to increase this.
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| bower5932 |
| Posted: Thu Nov 29, 2007 5:26 am Post subject: |
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Jedi Knight
Joined: 27 Aug 2001
Posts: 3023
Location: Dallas, TX, USA
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| fjb_saper |
| Posted: Thu Nov 29, 2007 1:33 pm Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| jefflowrey wrote: |
You probably need more connections than you think you do, for a JMS App Server MDB - about two or three per instance of the MDB.
So you may just need to get your MQ Admin to increase this. |
Usually per inbound MDB with no outbound JMS connections:
connections needed = number of max instances of the MDB + 1.
Note that the same MDB used with a different name (code reusage) and linked to a different or the same queue will count as 2 different MDBs in the previous requirement. 
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| niraj.chaudhary |
| Posted: Thu Dec 13, 2007 11:40 pm Post subject: |
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Novice
Joined: 20 Jun 2007
Posts: 22
Location: UK
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I still am facing the same problem. I have not been able to find any API using which I can close the conneciton properly. I did follow some suggestin and my code looks like this right now. ( it's deployed on Weblogic 8.1):
private void putMessage(String msg) throws JMSException, Exception
{
PCK pck = new PCK();
QueueConnection queueConnection = null;
QueueSession queueSession = null;
QueueSender queueSender = null;
try
{
if (queueConnectionFactory != null)
{
queueConnection = queueConnectionFactory.createQueueConnection();
queueSession = queueConnection.createQueueSession(false,Session.AUTO_ACKNOWLEDGE);
queueSender = queueSession.createSender(queue);
Message message = queueSession.createTextMessage(msg);
queueSender.send(message);
RH01Log.log("emw_00570","Message send [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
}
}
catch (JMSException jEx)
{
RH01Log.log("emw_00570","JMSException while sending the message["+jEx.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
Exception ex = jEx.getLinkedException();
if (ex != null)
{
RH01Log.log("emw_00570","Linked Exception["+ex.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
}
throw jEx;
}
catch (Exception e)
{
RH01Log.log("emw_00570","Exception while sending the message["+e.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
throw e;
}
finally
{
try
{
if (queueSender != null)
{
RH01Log.log("emw_00570","Closing Sender [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
queueSender.close();
}
}
catch (JMSException jEx)
{
Exception ex = jEx.getLinkedException();
if (ex != null)
{
RH01Log.log("emw_00570","Linked Exception while closing queueSender["+ex.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
}
throw jEx;
}
catch (Exception e)
{
RH01Log.log("emw_00570","Exception while closing the queueSender["+e.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
throw e;
}
try
{
if (queueSession != null)
{
RH01Log.log("emw_00570","Closing Session [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
queueSession.close();
}
}
catch (JMSException jEx)
{
Exception ex = jEx.getLinkedException();
if (ex != null)
{
RH01Log.log("emw_00570","Linked Exception while closing queueSession["+ex.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
}
throw jEx;
}
catch (Exception e)
{
RH01Log.log("emw_00570","Exception while closing the queueSession["+e.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
throw e;
}
try
{
if (queueConnection != null)
{
RH01Log.log("emw_00570","Closing Connection [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
queueConnection.close();
}
}
catch (JMSException jEx)
{
Exception ex = jEx.getLinkedException();
if (ex != null)
{
RH01Log.log("emw_00570","Linked Exception while closing queueConnection["+ex.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
}
throw jEx;
}
catch (Exception e)
{
RH01Log.log("emw_00570","Exception while closing the queueConnection["+e.getMessage()+"] [com.XXXXX.rbsc.mdb.TsrRbscApiMDB(putMessage())]" ,pck,"");
throw e;
}
}
}
It's part of an MDB, where context look up for queue and queue conneciton factory is done in the create method. Any suggestions?? |
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| fjb_saper |
| Posted: Fri Dec 14, 2007 8:21 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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Well if this is part of the onMessage method of the MDB you will need :
2 X max(MDB instances) + 1 connections so 11 connections for 5 MDB instances...
Enjoy 
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| niraj.chaudhary |
| Posted: Sun Dec 16, 2007 10:49 pm Post subject: |
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Novice
Joined: 20 Jun 2007
Posts: 22
Location: UK
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hi,
In my case i have got 2 mdb's and max instance possible for both of them are 10. So, going by your logic, i should have 41 server connection channels. While I actually have 100 and despite this I am facing this issue. Even load wasn't great.
Any other suggestions!
cheers,
Niraj |
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| fjb_saper |
| Posted: Mon Dec 17, 2007 4:35 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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WAS settings will influence as well as transactionality.
If you have outbound connection not driven by inbound connections you need to estimate the number of concurrent connections your web app might need... perhaps based on web traffic...
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