Help : Message Driven bean seeing the same message multiple times.

Question

( We are using weblogic 8.1 on Solaris )
We have a bunch of message driven beans with the transaction type as 'Container' and the acknowledge-mode mode as auto-acknowledge. They are consuming messages from a weblogic Queue ( javax.jms.Queue ). The MBD container is also weblogic 8.1.
We have 7 instances of the bean consuming messages.
Most of the messages are picked up and processed only once as expected.
But randomly we are seeing that sometimes the same message is delivered again ( Message.getJmsRedelivered = true ) eventhough it was once picked up and processed successfully once.
We are completely lost and our production machine is in big trouble as a result of this.
( Is it possible that weblogic uses unreliable UDP for acknowledging messages. If yes where do we change this setting )
Any help will be greatly appreciated
Thanks
--sony
================ejb-jar.xml BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>
<ejb-jar>
<enterprise-beans>
<message-driven>
<description>DslUpdtDdpostPrcsrMDB</description>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<ejb-class>
com.bellsouth.snt.idm.ejb.wfac.DslUpdtDdpostPrcsrMDB
</ejb-class>
<transaction-type>Container</transaction-type>
<message-selector>
<![CDATA[ idm_state = 'dsl_updt_dd_post' ]]>
</message-selector>
<acknowledge-mode>auto-acknowledge</acknowledge-mode>
<message-driven-destination>
<destination-type>javax.jms.Queue</destination-type>
</message-driven-destination>
<env-entry>
          <env-entry-name>MDB_NAME</env-entry-name>
          <env-entry-type>java.lang.String</env-entry-type>
          <env-entry-value>dsl_updt_dd_post</env-entry-value>
</env-entry>
<!--security-identity><use-caller-identity/></security-identity-->
<resource-ref>
<res-ref-name>jms/QueueConnectionFactory</res-ref-name>
<res-type>javax.jms.QueueConnectionFactory</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
</message-driven>
</enterprise-beans>
<assembly-descriptor>
<container-transaction>
<method>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
</ejb-jar>
================ejb-jar.xml END
================weblogic-ejb-jar.xml BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic 8.1.0 EJB//EN' 'http://www.bea.com/servers/wls810/dtd/weblogic-ejb-jar.dtd'>
<weblogic-ejb-jar>
<weblogic-enterprise-bean>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<message-driven-descriptor>
<pool>
<max-beans-in-free-pool>10</max-beans-in-free-pool>
<initial-beans-in-free-pool>0</initial-beans-in-free-pool>
</pool>
<destination-jndi-name>
idm.jms.clip.WfacClipResponseQueue
</destination-jndi-name>
<connection-factory-jndi-name>
idm.jms.IdmXaJmsQueueConnectionFactory
</connection-factory-jndi-name>
</message-driven-descriptor>
<transaction-descriptor>
<trans-timeout-seconds>
300
</trans-timeout-seconds>
</transaction-descriptor>
<reference-descriptor>
<resource-description>
<res-ref-name>jms/QueueConnectionFactory</res-ref-name>
<jndi-name>idm.jms.IdmXaJmsQueueConnectionFactory</jndi-name>
</resource-description>
</reference-descriptor>
<jndi-name>jms.DslUpdtDdpostPrcsrMDB</jndi-name>
</weblogic-enterprise-bean>
</weblogic-ejb-jar>
================weblogic-ejb-jar.xml END

Answer 1

The transaction attribute for the MDB is set to 'Required'. Is it possible
that your application logic may process the message successfully even in
case of a transaction roll back? If the transaction rolls back, the message
will be re-delivered.
There is some docs on exactly-once processing which may help
http://e-docs.bea.com/wls/docs81/ejb/message_beans.html#1147208
--Sathish
<Sony Antony> wrote in message news:[email protected]...
( We are using weblogic 8.1 on Solaris )
We have a bunch of message driven beans with the transaction type as
'Container' and the acknowledge-mode mode as auto-acknowledge. They are
consuming messages from a weblogic Queue ( javax.jms.Queue ). The MBD
container is also weblogic 8.1.
We have 7 instances of the bean consuming messages.
Most of the messages are picked up and processed only once as expected.
But randomly we are seeing that sometimes the same message is delivered
again ( Message.getJmsRedelivered = true ) eventhough it was once picked
up and processed successfully once.
We are completely lost and our production machine is in big trouble as a
result of this.
( Is it possible that weblogic uses unreliable UDP for acknowledging
messages. If yes where do we change this setting )
Any help will be greatly appreciated
Thanks
--sony
================ejb-jar.xml BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise
JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>
<ejb-jar>
<enterprise-beans>
<message-driven>
<description>DslUpdtDdpostPrcsrMDB</description>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<ejb-class>
com.bellsouth.snt.idm.ejb.wfac.DslUpdtDdpostPrcsrMDB
</ejb-class>
<transaction-type>Container</transaction-type>
<message-selector>
<![CDATA[ idm_state = 'dsl_updt_dd_post' ]]>
</message-selector>
<acknowledge-mode>auto-acknowledge</acknowledge-mode>
<message-driven-destination>
<destination-type>javax.jms.Queue</destination-type>
</message-driven-destination>
<env-entry>
<env-entry-name>MDB_NAME</env-entry-name>
<env-entry-type>java.lang.String</env-entry-type>
<env-entry-value>dsl_updt_dd_post</env-entry-value>
</env-entry>
<!--security-identity><use-caller-identity/></security-identity-->
<resource-ref>
<res-ref-name>jms/QueueConnectionFactory</res-ref-name>
<res-type>javax.jms.QueueConnectionFactory</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
</message-driven>
</enterprise-beans>
<assembly-descriptor>
<container-transaction>
<method>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
</ejb-jar>
================ejb-jar.xml END
================weblogic-ejb-jar.xml BEGIN
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic
8.1.0 EJB//EN'
'http://www.bea.com/servers/wls810/dtd/weblogic-ejb-jar.dtd'>
<weblogic-ejb-jar>
<weblogic-enterprise-bean>
<ejb-name>DslUpdtDdpostPrcsrMDB</ejb-name>
<message-driven-descriptor>
<pool>
<max-beans-in-free-pool>10</max-beans-in-free-pool>
<initial-beans-in-free-pool>0</initial-beans-in-free-pool>
</pool>
<destination-jndi-name>
idm.jms.clip.WfacClipResponseQueue
</destination-jndi-name>
<connection-factory-jndi-name>
idm.jms.IdmXaJmsQueueConnectionFactory
</connection-factory-jndi-name>
</message-driven-descriptor>
<transaction-descriptor>
<trans-timeout-seconds>
300
</trans-timeout-seconds>
</transaction-descriptor>
<reference-descriptor>
<resource-description>
<res-ref-name>jms/QueueConnectionFactory</res-ref-name>
<jndi-name>idm.jms.IdmXaJmsQueueConnectionFactory</jndi-name>
</resource-description>
</reference-descriptor>
<jndi-name>jms.DslUpdtDdpostPrcsrMDB</jndi-name>
</weblogic-enterprise-bean>
</weblogic-ejb-jar>
================weblogic-ejb-jar.xml END