java/org/apache/catalina/Cluster.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina;

/**
 * A <b>Cluster</b> works as a Cluster client/server for the local host Different Cluster implementations can be used to
 * support different ways to communicate within the Cluster. A Cluster implementation is responsible for setting up a
 * way to communicate within the Cluster and also supply "ClientApplications" with <code>ClusterSender</code> used when
 * sending information in the Cluster and <code>ClusterInfo</code> used for receiving information in the Cluster.
 *
 * @author Bip Thelin
 * @author Remy Maucherat
 */
public interface Cluster extends Contained {

    /**
     * Return the name of the cluster that this Server is currently configured to operate within.
     *
     * @return The name of the cluster associated with this server
     */
    String getClusterName();


    /**
     * Set the name of the cluster to join, if no cluster with this name is present create one.
     *
     * @param clusterName The clustername to join
     */
    void setClusterName(String clusterName);


    /**
     * Create a new manager which will use this cluster to replicate its sessions.
     *
     * @param name Name (key) of the application with which the manager is associated
     *
     * @return The newly created Manager instance
     */
    Manager createManager(String name);


    /**
     * Register a manager with the cluster. If the cluster is not responsible for creating a manager, then the container
     * will at least notify the cluster that this manager is participating in the cluster.
     *
     * @param manager Manager
     */
    void registerManager(Manager manager);


    /**
     * Removes a manager from the cluster
     *
     * @param manager Manager
     */
    void removeManager(Manager manager);


    /**
     * Execute a periodic task, such as reloading, etc. This method will be invoked inside the classloading context of
     * this container. Unexpected throwables will be caught and logged.
     */
    void backgroundProcess();
}