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Re: Weird Message Driven Bean Behavior

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mvatkina
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Joined: 2005-04-04
Points: 0

Nigel Deakin wrote:
>> On the other side we have a JEE app (in the same glassfish server)
>> which has
>> a MDB to get the message and process it... All was fine but then a
>> week ago
>> we started seeing some weird issue where the MessageProducer is
>> putting a
>> message in the queue and it takes up to 4 seconds for the MDB to grab
>> it.
>
> Remember you've got a pool of MDB instances running in your GlassFish
> server. If they're all busy processing messages then when a new
> message arrives it can't be processed until a MDB instance becomes
> available.

GlassFish will create as many instances as necessary, but there can be
not enough threads, or the JCA adapter might be capping the amount of
messages it processes at once.
> Do you see this problem when the load is very low and there are lots
> of free MDB instances?
>
> When you see the problem, does it continue for ever or does it go away
> after a while?
>
>> One other thing, the MDB is not in a regular EJB jar, it is in a
>> hybrid osgi
>> bundle.
>
> That's probably not the cause of the issue.
>
>> We are trying to recreate the problem in our performance test
>> envrionment but
>> we cannot recreate it. Has anyone seen this or have any clue if we
>> need to
>> fix some parameter to prevent this from happening?
>
> A standard piece of advice is to check both the GlassFish server log
> and the JMS broker log for unusual entries (Say if you don't know how
> to find the latter).
>
> Nigel
>
>