Apache Tribes - The Tomcat Cluster Communication Module

Tribes exposes the state of a running channel through JMX. Use a JMX client to inspect the channel and its components. See the Tomcat monitoring documentation for ways to connect a JMX client.

The channel's jmxEnabled attribute controls registration and defaults to true. The default JMX domain is ClusterChannel; jmxDomain and jmxPrefix can change the object names. Each object name includes type=Channel, the channel name, and a component property. A channel must have a name for its components to register. See the channel configuration for these attributes.

The component=Membership MBean exposes the the members known to this node. Multicast, static, and cloud membership services expose hasMembers and getMembersByName. A single node cluster has no remote members.

The component=Receiver MBean for an NIO receiver exposes Listening, ActiveCount, and PoolSize. The component=Sender MBean exposes properties of the configured sender.

If a ThroughputInterceptor is configured, its component=Interceptor MBean exposes transmitted and received message counts and transmit errors. A MessageDispatchInterceptor exposes CurrentSize and worker counts for its asynchronous send queue. Interceptor MBeans are present only for configured interceptors.

When Tribes is used by a Tomcat cluster, the session manager provides additional replication statistics. For example, a DeltaManager with statistics enabled exposes counters for sent and received session events and state transfers. These are manager statistics, separate from the channel component MBeans. See the cluster manager configuration for the enableStatistics attribute.