This section describes how to configure the WSO2 ESB's JMS transport with ActiveMQ.
Setting up WSO2 ESB and ActiveMQ
Follow the instructions below to set up and configure.
1. Download, set up and start Apache ActiveMQ.
2. Follow the Getting Started and set up WSO2 ESB.
ActiveMQ should be up and running before starting the ESB.
3. Copy the following client libraries from the
<AMQ_HOME>/lib directory to the
ActiveMQ 5.8.0 and above
- activeio-core-3.1.4.jar (available in
Earlier version of ActiveMQ
4. Next, configure transport listeners and senders in ESB.
When configuring JMS with ActiveMQ, you can append ActiveMQ-specific properties to the value of the
java.naming.provider.url property. For example, you can set the
initialRedeliveryDelay properties when configuring a JMS inbound endpoint as follows:
Setting up the JMS Listener
To enable the JMS transport listener, un-comment the following listener configuration related to ActiveMQ in <ESB_HOME>/repository/conf/axis2/axis2.xml file.
Setting up the JMS Sender
To enable the JMS transport sender, un-comment the following configuration in <ESB_HOME>/repository/conf/axis2/axis2.xml file.
The above configurations do not address the problem of transient failures of ActiveMQ message broker. Let's say for some reason ActiveMQ goes down and comes back up after a while. ESB won't reconnect to ActiveMQ but instead it'll throw some errors as requests are sent to ESB till it is restarted. In order to tackle this issue one needs to add the following configuration in the place of the java.naming.provider.url,
This will simply make sure re-connection takes place when ActiveMQ is up and running. Failover prefix is associated with the Failover Transport of ActiveMQ. For further information about this please try The Failover Transport.
You now have instances of ActiveMQ and WSO2 ESB configured, up and running. Next, refer to section JMS Usecases for implementation details of various JMS use cases.
When working with JMS message stores, if you are using ActiveMQ 5.12.2 and above, you need to set the following system property on server start up for WSO2 ESB's JMS message store to work as expected.
With ActiveMQ 5.12.2 and above, you need to set the above property because users are enforced to explicitly whitelist packages that can be exchanged using ObjectMessages, and due to this restriction the message processor fails to read messages from ActiveMQ with the following error:
Connecting multiple ActiveMQ brokers
The WSO2 ESB can be configured as explained in the following procedure in order to work with two ActiveMQ brokers. In this example, port 61616 is used for one ActiveMQ instance and port 61617 is used for the other.
- Configure the ESB to work with one ActiveMQ broker as described above.
- Start another ActiveMQ instance.
Add another transport receiver to the <ESB_Home>/repository/conf/axis2/axis2.xml file as follows. Note that the name of the transport receiver is different to that of the transport receiver already entered. The port specified is
- Set up the JMS sender as explained in Setting up the JMS sender.
Configuring Redelivery in ActiveMQ Queues
When WSO2 ESB is configured to consume messages from an ActiveMQ queue, you have the option to configure message re-delivery. This is useful when messages are unable to be processed by ESB due to failures.
- Enable the JMS listener as explained in Setting up the JMS listener.
Add the following JMS parameters into the proxy service configuration in WSO2 ESB:
redeliveryPolicy.maximumRedeliveries: Maximum number of retries for delivering the message. If set to -1 ActiveMQ will retry inifinitely.
transport.jms.SessionTransacted: When set to
true, this enables the JMS session transaction for the proxy service.
redeliveryPolicy.redeliveryDelay: Delay time in milliseconds between retries.
transport.jms.CacheLevel: This needs to be set to
consumerfor the ActiveMQ redelivery mechanism to work.
Add the following line in your fault sequence:
<property name="SET_ROLLBACK_ONLY" value="true" scope="axis2"/>
SET_ROLLBACK_ONLYThis parameter must be defined for ActiveMQ to redeliver the message.When ESB is unable to deliver a message to the back-end service due to an error, it will be routed to the fault sequence in the ESB configuration. When "SET_ROLLBACK_ONLY" property is set in the fault sequence, ESB informs ActiveMQ to redeliver the message.
Below is a sample proxy service configuration: