8.16. Channel Fail-Over

The HelloWorld Service can listen to multiple protocols. Here we have added a JMS channel: 
...
<service category="FirstServiceESB" name="SimpleListener" description="Hello World">
    <listeners>
        <jms-listener name="helloWorld"  busidref="quickstartEsbChannel" maxThreads="1"/>
        <jms-listener name="helloWorld2" busidref="quickstartFtpChannel2" maxThreads="1"/>
    </listeners>
...
The service is simultaneously listening to two JMS queues which can be provided by JMS providers on different physical boxes. This makes a JMS connection between two services redundant. You can also mix protocols in this configuration. For instance, this code show how to add an FTP listener. 
...
<service category="FirstServiceESB" name="SimpleListener"
 description="Hello World">
 <listeners>
  <jms-listener name="helloWorld" busidref="quickstartEsbChannel"
 maxThreads="1"/>
  <jms-listener name="helloWorld2" busidref="quickstartJmsChannel2"
 maxThreads="1"/>
  <ftp-listener name="helloWorld3" busidref="quickstartFtpChannel3"
 maxThreads="1"/>
  <ftp-listener name="helloWorld4" busidref="quickstartFtpChannel3"
 maxThreads="1"/>
 </listeners>
...

Note

When the ServiceInvoker tries to deliver a message to the Service it will get a choice of eight end-point references (four EPRs from Node1 and four EPRs from Node2). To define which one will be used, configure a load-balancing policy.