[LONG]Tomcat clustering enabling GBeans howto - Part 1

[Jeff Genender]

Hi,

First, I would recommend that you have a good understanding of how 
Tomcat clustering works.  See:

http://tomcat.apache.org/tomcat-5.5-doc/cluster-howto.html

Now..a disclaimer...

All I did was enable the Tomcat clustering and extend it into Geronimo. 
 This means that 99% of it should work.  The 1% is the deployment 
issues.  Although I exposed the FarmDeployer, I think there may be 
issues with it since it may bypass the Geronimo deployment.  Although it 
*might* work...I would think something like this needs to be run through 
the Geronimo.  Rather than spend a tremendous amount of time in this 
area on the Tomcat code, I would probably recommend that this type of 
code be a plugin to WADI, since it is my hope that it will ultimately be 
the eventual clustering and caching solution for Geronimo.

Enabling simple clustering at the Engine level:

In the j2ee-tomcat-plan.xml, lets create a simple clustering Gbean for 
Tomcat:

    <!-- Cluster -->
    <gbean name="TomcatCluster" 
class="org.apache.geronimo.tomcat.cluster.CatalinaClusterGBean">
        <attribute 
name="className">org.apache.catalina.cluster.tcp.SimpleTcpCluster</attribute>
    </gbean>

Then we need to set the jvmRoute for the Engine (make it different for 
each Geronimo instance that you run), and set the "CatalinaCluster" 
attribute...so we want the Engine Gbean to look like the following:

    <!-- Engine -->
    <gbean name="TomcatEngine" 
class="org.apache.geronimo.tomcat.EngineGBean">
        <attribute
name="className">org.apache.geronimo.tomcat.TomcatEngine</attribute>
        <attribute name="initParams">
            name=Geronimo
            defaultHost=0.0.0.0
            jvmRoute=node1
        </attribute>
        <references name="Hosts">
            <pattern>
                <gbean-name>geronimo.server:j2eeType=Host,*</gbean-name>
            </pattern>
        </references>
        <reference name="RealmGBean">
            <name>TomcatJAASRealm</name>
        </reference>
        <reference name="TomcatValveChain">
            <name>FirstValve</name>
        </reference>
        <reference name="CatalinaCluster">
            <name>TomcatCluster</name>
        </reference>
    </gbean>