001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.transport.discovery;
018
019import java.io.IOException;
020
021import javax.jms.JMSException;
022
023import org.apache.activemq.Service;
024import org.apache.activemq.command.DiscoveryEvent;
025
026/**
027 * An agent used to discover other instances of a service. 
028 * 
029 * We typically use a discovery agent to auto-discover JMS clients and JMS brokers on a network
030 *
031 * 
032 */
033public interface DiscoveryAgent extends Service {
034
035    /**
036     * Sets the discovery listener
037     * @param listener
038     */
039    void setDiscoveryListener(DiscoveryListener listener);
040
041    /**
042     * register a service
043     * @param name
044     * @param details
045     * @throws JMSException
046     */
047    void registerService(String name) throws IOException;
048    
049    /**
050     * A process actively using a service may see it go down before the DiscoveryAgent notices the
051     * service's failure.  That process can use this method to notify the DiscoveryAgent of the failure
052     * so that other listeners of this DiscoveryAgent can also be made aware of the failure.
053     */
054    void serviceFailed(DiscoveryEvent event) throws IOException;
055    
056}