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Re: [SPAM] - Re: Regarding restricting number of instant for MDB - Found word(s) list error in the Text body.

Kamaraj, Pushparaj

2004-07-19

Replies:

Hi,
Thank you very much Binidas.

    If I explain the scenario it will be better for understanding.

    We have a program, which will do some complex calculation, which
needs to be triggered asynchronously from screen, and the process may take
15 mins to complete. The screen will not wait until the calculation is
complete. This is the reason we preferred JMS and MDB. The screen event will
put the message into the queue and JMS will hand over the message to MDB for
processing.

  Is it a correct approach?

    Assume the Object pool size is 5 and there are 6 concurrent users
are doing the operation which will end up in 6 messages. As the Object pool
size is 5, all the pool instant will be used, for 6th message, as there is
no object is free in the pool the system will instantiated a new one. The
same way if there are 25 concurrent messages there is a possibility 25
instant may be running.

  Is my understanding correct?

    The requirement is if the pool size is 5 and already all the objects
in the pool is under use then the 6th message needs to wait in the queue
until one object is returned to the pool. For that what configuration needs
to be done?.

Kind regards,
K.Pushparaj.



> -----Original Message-----
> From: Binildas C. A. [SMTP:binil_christudas@(protected)]
> Sent: Monday, July 19, 2004 12:33 PM
> To:  J2EEPATTERNS-INTEREST@(protected)
> Subject:    [SPAM] - Re: Regarding restricting number of instant for MDB
> - Found word(s) list error in the Text body.
>
> Hi
>
> Instead of "If the system start associating a MDB for each message ", The
> system will associate some instance of the MDB which is already available
> in
> the pool for each message. This means, for each individual message, we
> dont
> end up with each seperate MDB instance. Instead, MDB instances get reused
> (Object pooling). This is the very use of using MDB than a standalone JMS
> listener(of course, with other features like TX, etc...)
>
> Instead of "for each message then there will be many processes running in
> parallel" , we can re-write as follows:
> For each message, container wont start seperate process, and not even a
> seperate thread. Instead, container will chose a thread from the thread
> pool, and associate that thread to the chosed MDB context, and the message
> will be served by this MDB.
>
> Now, to tune the number of MDBs and all - This a task which we need to do
> taking into consideration things like:
>
> 1. App Server
> 2. Size of application
> 3. Other applications in server
> 4. Frequency of messages
> 5. Time to serve each message
> 6...
> The list goes like this...
>
> Binildas
> Sr. Tech. Architect
> http://www.infosys.com/setlabs/)
>
> ----- Original Message -----
> From: "Kamaraj, Pushparaj" <Pushparaj_Kamaraj@(protected)>
> To: <J2EEPATTERNS-INTEREST@(protected)>
> Sent: Monday, July 19, 2004 12:33 PM
> Subject: Regarding restricting number of instant for MDB
>
>
> > Hi,
> >      We are having Message driven bean and other session beans in the
> > same container.
> >      The characteristics of MDB is whenever a message is added to the
> JMS
> > queue it will be instantiated to serve the message.
> >      We are expecting there will be large number of messages coming
> to
> > JMS queue. If the system start associating a MDB for each message then
> there
> > will be many processes running in parallel, which will reduce the system
> > performance. How to restrict the maximum number of active MDB in the
> system?
> > And the configuration should not affect other session bean instants. If
> we
> > restrict the maximum instant to 10, at the most there will be only 10
> MDBs
> > and other request will be waiting in the JMS queue.
> >
> >      We are using the following configuration to achieve the above
> > requirement. Is that correct?
> >
> > <message-driven-descriptor>
> >                 <pool>
> >
> > <max-beans-in-free-pool>6</max-beans-in-free-pool>
> >
> > <initial-beans-in-free-pool>3</initial-beans-in-free-pool>
> >                 </pool>
> >           </message-driven-descriptor>
> >
> > Thanks,
> > K.Pushparaj.
> >
> > ____________________________________________
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____________________________________________
Confidential: This electronic message and all contents contain information
from Syntel, Inc. which may be privileged, confidential or otherwise
protected from disclosure. The information is intended to be for the
addressee only. If you are not the addressee, any disclosure, copy,
distribution or use of the contents of this message is prohibited. If you
have received this electronic message in error, please notify the sender
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