Page Comparison

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  /*
   * Creates a JMS connection with the default user identity. The connection is
    * created in stopped mode. No messages will be delivered until the
    * Connection.start method is explicitly called.
   *
    * @return a newly created JMS connection. May return null
   *
    */
   public Connection createConnection();
	
  /*
   * Creates a JMS connection with the specified user identity. The connection is
    * created in stopped mode. No messages will be delivered until the 
   * Connection.start method is explicitly called.
   * 
   * @parameter userName - the caller's user name
   * @parameter password - the caller's password
   * 
   * @return a newly created JMS connection. May return null
   */
   public Connection createConnection(String userName, String password);
	
  /*
   * Gets the JMS Connection with the specified user identity, configured in components.xml
   * The connection is returned in start mode.
   *
    * @return the initially created JMS Connection object. May return null
   *
    */
   public Connection getConnection();

Usage with Spring (Sakai 2.5)

  <!-- definition of a message producer -->
  <bean id="org.sakaiproject.messageservice.test.MessageProducer"
    class="org.sakaiproject.messageservice.test.MessageProducerImpl">
      <property name="connectionFactory"
        ref="org.sakaiproject.messageservice.JmsConnectionFactory" />
      <property name="queueName" value="test.destination" />
  </bean>

  <!-- definition of listner container -->
  <bean id="listenerContainer"
    class="org.springframework.jms.listener.DefaultMessageListenerContainer"
    depends-on="org.sakaiproject.messageservice.JmsConnectionFactory">
      <property name="concurrentConsumers" value="1" />
      <property name="maxConcurrentConsumers" value="1" />
      <property name="connectionFactory"
        ref="org.sakaiproject.messageservice.JmsConnectionFactory" />
      <property name="destinationName" value="test.destination" />
      <!-- set pubSubDomain to false to create a queue instead of a Publish/Subscribe topic -->
      <property name="pubSubDomain" value="true"/>
      <property name="messageListener">
	<bean class="org.sakaiproject.messageservice.test.MessageListenerImpl"/>
      </property>
  </bean>

...

• JMS Connection Object
  • Usually there is no need to create more than one JMS Connection object, and the ActiveMQ documentation and AQM Forum posts recommend to create/use only one connection object per server. Thus, in Sakai, we should use only one connection by calling getConnection(). In rare cases, it's justified to create a second connection.
• JMS Session
  • I asked about JMS session usage in the ActiveMQ forum, and here is the thread:
    • http://www.nabble.com/Using-one-session-per-message-to15114117s2354.html

Configuring

• Sakai Properties

  Property

  Default Value

  Comments

  jms.useJMX

  false

  If you have tomcat configured to allow JMX access, I would recommend to enable this setting as it greatly helps during the development process

  jms.brokerURL

  tcp://localhost:61616

  -

  jms.brokerDataPath

  sakai-home location

  This is either in "tomcat/sakai" or the location defined by JAVA_OPTS "-Dsakai.home=/path/to/sakai-home/"changing the persistence adapter
  The persistence adapter can be changed in sakai.properties or local.properties.
  property name:
  targetBeanName@org.sakaiproject.messageservice.activemq.PersistenceAdapter
  default value:
  org.sakaiproject.messageservice.activemq.AMQPersistenceAdapter
  possible persistence adapters:
  org.sakaiproject.messageservice.activemq.AMQPersistenceAdapter
  org.sakaiproject.messageservice.activemq.JournalPersistenceAdapter
  org.sakaiproject.messageservice.activemq.JdbcPersistenceAdapter

• enable clustered broker
  By default the broker is configured to run in standalone mode. To enable a clustered environment and auto discovery the following change have to be applied to activemq-beans.xml

  No Format

  <bean id="org.sakaiproject.messageservice.JmsConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory"> <property name="brokerURL" value="discovery:(multicast://sakai)"/> </bean> <bean id="org.sakaiproject.messageservice.activemq.TransportConnector" class="org.apache.activemq.broker.TransportConnector" lazy-init="true"> <property name="name" value="default" /> <property name="uri" ref="org.sakaiproject.messageservice.api.BrokerUrl" /> <property name="discoveryUri" ref="org.sakaiproject.messageservice.api.DiscoveryUrl"/> </bean> <bean id="org.sakaiproject.messageservice.activemq.NetworkConnectorListFactory" class="org.springframework.beans.factory.config.BeanReferenceFactoryBean" lazy-init="true"> <property name="targetBeanName" value="org.sakaiproject.messageservice.activemq.DiscoveryNetworkConnectorList" /> </bean>

• changing other Broker properties

  Property	Default	Comments
  persistent@org.sakaiproject.messageservice.broker.BrokerService	true
  useJmx@org.sakaiproject.messageservice.broker.BrokerService	true
  targetBeanName@org.sakaiproject.messageservice.api.BrokerUrlStringFactory	org.sakaiproject.messageservice.api.BrokerUrlString (tcp://localhost:61616?wireFormat.maxInactivityDuration=0)	other valid bean name, that defines a url string

• On each application node, you need to enable the following ports and protocols in your host based firewall
  • TCP port 61616
  • UDP port 6155
  • e.g. Linux iptables

    No Format
    -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -s 192.168.1.0/24 --dport 61616 -j ACCEPT -A RH-Firewall-1-INPUT -m state --state NEW -m udp -p udp -s 192.168.1.0/24 --dport 6155 -j ACCEPT

...