Tomcat Cluster

Setup Tomcat Cluster environment

• Refer to Tomcat Document to set up cluster environment.
• For configuring with Apache http server, refer to
  • How to Run ZK on Apache + Tomcat clustering, Part I
  • How to Run ZK on Apache + Tomcat clustering, Part II

Using more than 3 nodes with ZK

• Using DeltaManager instead of BackupManager, refer to cluster-manager for more information.

Additional setting in ZK project

You have to configure the following settings to make ZK project work in tomcat cluster environment.

web.xml

• Add the distributable element in WEB-INF/web.xml.

<?xml version="1.0"?>
<web-app  xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">

    <distributable/>

</web-app>

zk.xml

• Turn on Serializable UI Factory for ZK, please refer to this documentation.
• If Tomcat cluster nodes is large than 3, also need to add cluster session patch.

For example,

<zk>
    <system-config>
        <ui-factory-class>org.zkoss.zk.ui.http.SerializableUiFactory</ui-factory-class>
    </system-config>
    <!-- clustering environment, since ZK 5.0.8-->
    <listener>
        <listener-class>org.zkoss.zkplus.cluster.ClusterSessionPatch</listener-class>
    </listener>
</zk>