Advertise allows autodiscovery of httpd proxies by the cluster nodes. It is done by sending multicast messages from httpd to the cluster. The httpd specialized module: mod_advertise sends UDP message on a multicast group, both mod_advertise and the cluster listener joined the multicast group and the cluster receives the messages.

Example for mod_advertise message:

HTTP/1.0 200 OK

 Date: Wed, 08 Apr 2009 12:26:32 GMT

 Sequence: 16

 Digest: f2d5f806a53effa6c67973d2ddcdd233

 Server: 1b60092e-76f3-49fd-9f99-a51c69c89e2d

 X-Manager-Address: 127.0.0.1:6666

 X-Manager-Url: /bla

 X-Manager-Protocol: http

 X-Manager-Host: 10.33.144.3

The X-Manager-Address header value is used by the cluster logic to send information about the cluster to the proxy. It is the IP and port of the VirtualHost where mod_advertise is configured or URL parameter of the ServerAdvertise directive.

See Proxy Discovery in Configuration Properties and mod_advertise in Apache httpd configuration.

In the VirtualHost receiving the MCPM of httpd.conf don't use any Advertise directive or use:

ServerAdvertise Off

In mod_cluster-jboss-beans.xml add the addresses and ports of the VirtualHost to the proxyList property and set advertise to false, for example:

<property name="proxyList">10.33.144.3:6666,10.33.144.1:6666</property>

<property name="advertise">false</property>

See at the end of java configuration You can't use the mod_cluster clustered mode with Tomcat so you get a loadbalancing logic similar to mod_jk but with a dynamic configuration.