Finally, we must configure the JBoss Tomcat instances on all clustered nodes so that they can expect requests forwarded from the mod_jk loadbalancer.

On each clustered JBoss node, we have to name the node according to the name specified in workers.properties. For instance, on JBoss instance node1, edit the JBOSS_HOME/server/all/deploy/jboss-web.deployer/server.xml file (replace /all with your own server name if necessary). Locate the <Engine> element and add an attribute jvmRoute:

<Engine name="jboss.web" defaultHost="localhost" jvmRoute="node1">
... ...
</Engine>
            

You also need to be sure the AJP connector in server.xml is enabled (i.e., uncommented). It is enabled by default.

 
<!-- Define an AJP 1.3 Connector on port 8009 --> 
<Connector port="8009" address="${jboss.bind.address}" protocol="AJP/1.3" 
emptySessionPath="true" enableLookups="false" redirectPort="8443" /> 

Then, for each JBoss Tomcat instance in the cluster, we need to tell it that mod_jk is in use, so it can properly manage the jvmRoute appended to its session cookies so that mod_jk can properly route incoming requests. Edit the JBOSS_HOME/server/all/deploy/jbossweb-tomcat50.sar/META-INF/jboss-service.xml file (replace /all with your own server name). Locate the <attribute> element with a name of UseJK, and set its value to true:

<attribute name="UseJK">true</attribute>
            

At this point, you have a fully working Apache+mod_jk load-balancer setup that will balance call to the Servlet containers of your cluster while taking care of session stickiness (clients will always use the same Servlet container).