Can't use EJB3 MDB to retrieve messages one by one.

[bitl]

Hello!
I'll be as short as possible. Thank you.
Jboss version: 4.0.4RC1
EJB3 version: rc5-PFD
JRE: 1.5.0_06
My persistent queue config:

<mbean code="org.jboss.mq.server.jmx.Queue"
 name="jboss.mq.destination:service=Queue,name=myQueue1">
 <depends optional-attribute-name="DestinationManager">jboss.mq:service=DestinationManager</depends>
 <attribute name="MessageCounterHistoryDayLimit">-1</attribute>
</mbean>

My MDB class annotated:

@MessageDriven(activationConfig = {
@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
@ActivationConfigProperty(propertyName = "destination", propertyValue = "queue/myQueue1"),
@ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Client-acknowledge")
 })
public class BlogKsgMDBean implements MessageListener {

I'm using several threads to post messages to myQueue1 simultaneously.
Looking over my debug log I see that several instances of my MDB also starts simultaneously.
I would like to get it work to handle messages one by one.
No get next message from queue until current handle finish.
But still using MessageListener instead of .receive() method.
Is it possible? How do I have to configure it?
Here's how I post message:

conn = jmsConnectionFactory.createConnection();
//sess = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
sess = conn.createSession(false, Session.CLIENT_ACKNOWLEDGE);
producer = sess.createProducer((Destination) namingContext.lookup("queue/myQueue1"));
ObjectMessage msg = sess.createObjectMessage(message);
producer.send(msg);
producer.close();
sess.close();
conn.close();

[jaikiran]

MDBs are meant to start messages simultaneously.

[jaikiran]

start messages simultaneously

I meant, start processing messages simultaneously.

[mskonda]

use the Singleton configuration:

<message-driven>
 <configuration-name>Singleton Message Driven Bean</configuration-name>
 <ejb-name>XARecovery2ResMDB</ejb-name>
 <destination-jndi-name>queue/@QUEUE_NAME@</destination-jndi-name>
</message-driven>

[bitl]

"mskonda" wrote:
use the Singleton configuration:

<message-driven>
 <configuration-name>Singleton Message Driven Bean</configuration-name>
 <ejb-name>XARecovery2ResMDB</ejb-name>
 <destination-jndi-name>queue/@QUEUE_NAME@</destination-jndi-name>
</message-driven>

Thanks to all.

I explicitly added name to annotation:

@MessageDriven(name = "MyMDBean",

Created jboss.xml:

<jboss>
 <enterprise-beans>
 <message-driven>
 <ejb-name>MyMDBean</ejb-name>
 <destination-jndi-name>queue/myQueue1</destination-jndi-name>
 <configuration-name>Singleton Message Driven Bean</configuration-name>
 </message-driven>
 </enterprise-beans>
</jboss>

Got error:

2006-05-17 15:05:28,448 WARN [org.jboss.system.ServiceController] Problem creating service jboss.j2ee:service=EJB3,module=dvase-mdb.blog.ksg.jar
org.jboss.xb.binding.JBossXBException: Failed to parse source
 at org.jboss.xb.binding.parser.sax.SaxJBossXBParser.parse(SaxJBossXBParser.java:138)
...
Caused by: java.lang.ClassCastException: org.jboss.ejb3.dd.SessionEnterpriseBean
 at org.jboss.ejb3.dd.EnterpriseBeans.setDestinationJndiName(EnterpriseBeans.java:98)
 at org.jboss.ejb3.dd.JBossDDObjectFactory.setValue(JBossDDObjectFactory.java:697)
...
 at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
 at org.jboss.xb.binding.parser.sax.SaxJBossXBParser.parse(SaxJBossXBParser.java:134)

[mannef]

Did you figure out why you got this message, because I'm getting the exact same problem with an MDB on 4.0.4RC1.

Looks like a bug in the SaxJBossXBParser, because this is obviously no session EJB. Is this a known issue?

[bitl]

"ManneF" wrote:
Did you figure out why you got this message, because I'm getting the exact same problem with an MDB on 4.0.4RC1.

Looks like a bug in the SaxJBossXBParser, because this is obviously no session EJB. Is this a known issue?

Not yet.
Just have no time to dig it.
Currently I'm using ugly solution to synchronize onMessage method on static object.
Thus I no need to reprogram message reading but have something close to what I need.

[mannef]

You may want to consider using a database lock instead.

Using statics is inherently risky in a J2EE environment, because your class may be loaded many times by different class loaders.

[bitl]

"ManneF" wrote:
You may want to consider using a database lock instead.

Using statics is inherently risky in a J2EE environment, because your class may be loaded many times by different class loaders.

I got my MDBs to be always one per queue reducing their pool sizes:

@ActivationConfigProperty(propertyName = "MaxPoolSize", propertyValue = "1"),

Is it valid solution?

[bitl]

"mskonda" wrote:
use the Singleton configuration:

<message-driven>
 <configuration-name>Singleton Message Driven Bean</configuration-name>
 <ejb-name>XARecovery2ResMDB</ejb-name>
 <destination-jndi-name>queue/@QUEUE_NAME@</destination-jndi-name>
</message-driven>

I got my MDBs to be always one per queue reducing their pool sizes:

@ActivationConfigProperty(propertyName = "MaxPoolSize", propertyValue = "1"),

Is it a valid solution?