Configure mod_cluster for clustered mode
Clustered mode In clustered mode, a single JBoss node (the HA singleton master) communicates with the load balancer on behalf of the other nodes in the cluster. Clustered mode is configured via the HAModClusterService bean. This mode offers the following advantages over non-clustered mode: The state of the load balancer will be kept in sync on each node in the cluster. mod_cluster will proactively notify the load balancer of view changes (i.e. crashed members), allowing the load balancer to gracefully reconfigure itself thus avoiding costly failover processing. Clustered-mode allows load balancing group management, adding the ability to enable, disable, or gracefully stop all nodes sharing the same load balancing group. Once a given session is associated with a specific node, subsequent requests for the same session will always prefer to be routed to a node with the same load balancing group. Grouping nodes in this way is useful for limiting the number of nodes to which a given session must replicate to support high-availability. When used in conjunction with sessions affinity, a load balancing group effectively narrows the set of preferred failover nodes to members of the same load balancing group. A load balancing group is conceptually similar to a domain in mod_jk. In general, HAModClusterService defines: An object containing mod_cluster's configuration properties. An object responsible for calculating the load balance factor for this node. This is described in detail in the chapter entitled Server-Side Load Metrics. An HAPartition, the JBoss clustering group communication building block. The default HAPartition is defined in: $JBOSS_HOME/server/$PROFILE/deploy/cluster/hapartition-jboss-beans.xml A policy for determining which group member should be designated as the singleton master. e.g. @org.jboss.aop.microcontainer.aspects.jmx.JMX(name="jboss.web:service=ModCluster",exposedInterface=org.jboss.modcluster.ha.HAModClusterServiceMBean.class)