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.camel.cluster;
018
019import java.util.Optional;
020
021/**
022 * Marker interface for cluster events
023 */
024public interface CamelClusterEventListener {
025
026    interface Leadership extends CamelClusterEventListener {
027
028        /**
029         * Notify a change in the leadership for a particular cluster.
030         *
031         * @param view the cluster view
032         * @param leader the optional new leader
033         */
034        void leadershipChanged(CamelClusterView view, Optional<CamelClusterMember> leader);
035
036    }
037
038    interface Membership extends CamelClusterEventListener {
039
040        /**
041         * Notify a change (addition) in the cluster composition.
042         *
043         * @param view the cluster view
044         * @param member the member that has been added
045         */
046        void memberAdded(CamelClusterView view, CamelClusterMember member);
047
048        /**
049         * Notify a change (removal) in the cluster composition.
050         *
051         * @param view the cluster view
052         * @param member the member that has been removed
053         */
054        void memberRemoved(CamelClusterView view, CamelClusterMember member);
055
056    }
057}