Cluster

This article requires cleanup and may refer to a legacy version of Resin. Please visit http://www.caucho.com/documentation/ for the most up-to-date documentation.

A single Resin cluster, showing its controlling triad

• See http://www.caucho.com/resin/doc/resin-clustering.xtp for Resin 4.0 clustering documentation.
• See http://www.caucho.com/resin/doc/cluster-tags.xtp for Resin 4.0 <cluster> tag configuration.

A Resin cluster is a collection of servers which do the same task. For example, all the load-balance servers form a cluster and all the application-servers in the app-tier form a cluster.

Configuration

A cluster is configured in a <cluster> tag in the resin.conf.

• A set of servers, each with its own cluster port for cluster communication
• A set of virtual hosts, each containing several web-apps serving pages
• Shared resources like databases

example

For example, if you have two servers and a single virtual host "foo.com", a minimal resin.xml might look like the following:

resin.xml

<resin xmlns="http://caucho.com/ns/resin"
           xmlns:resin="http://caucho.com/ns/resin/core">
  <resin:import path="${__DIR__}/app-default.xml"/>
 
  <cluster id="app-tier">
     <server id="a" address="192.168.0.10" port="6800"/>
     <server id="b" address="192.168.0.11" port="6800"/>

    <host id="www.foo.com">
         <root-directory>/var/www/foo.com</root-directory>

        <web-app-deploy path="webapps"/>
     </host>
  </cluster>
</resin>

• <resin:import> defines standard behavior like *.jsp, *.php, the WEB-INF, and normal file serving. If you delete the app-default.xml import, your server will not work normally.
• <cluster> defines our servers and the virtual host
• <server> defines our static servers, i.e. the servers we'll always have available. The first three form the server triad
• <host> defines our single virtual host
• <root-directory> defines the location of the virtual host
• <web-app-deploy> specifies an auto-deploy directory for web-apps. Any *.war or directory created in webapps automaticaly creates a new application