1 /***
2 *
3 * Copyright 2004 Protique Ltd
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 **/
18
19 package org.codehaus.activecluster.election.impl;
20
21 import org.codehaus.activecluster.Cluster;
22 import org.codehaus.activecluster.Node;
23 import org.codehaus.activecluster.election.ElectionStrategy;
24
25 import javax.jms.JMSException;
26 import java.util.Iterator;
27 import java.util.Map;
28
29 /***
30 * <p><code>BullyElectionStrategy</code> Use a simple bully algorithm to elect a coordinator.
31 * the member with the lowest lexicographical name is choosen</p>
32 *
33 * @version $Revision: 1.2 $
34 */
35 public class BullyElectionStrategy implements ElectionStrategy {
36
37 /***
38 * Elect a coordinator.
39 *
40 * @param cluster
41 * @return the elected Node
42 * @throws JMSException
43 */
44 public Node doElection(Cluster cluster) throws JMSException {
45 Node elect = cluster.getLocalNode();
46
47 Map nodes = cluster.getNodes();
48 for (Iterator i = nodes.values().iterator(); i.hasNext();) {
49 Node node = (Node) i.next();
50 if (elect.getName().compareTo(node.getName()) < 0) {
51 elect = node;
52 }
53 }
54
55 return elect;
56 }
57
58 }