01: /*
02: * JBoss, Home of Professional Open Source.
03: * Copyright 2006, Red Hat Middleware LLC, and individual contributors
04: * as indicated by the @author tags. See the copyright.txt file in the
05: * distribution for a full listing of individual contributors.
06: *
07: * This is free software; you can redistribute it and/or modify it
08: * under the terms of the GNU Lesser General Public License as
09: * published by the Free Software Foundation; either version 2.1 of
10: * the License, or (at your option) any later version.
11: *
12: * This software is distributed in the hope that it will be useful,
13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15: * Lesser General Public License for more details.
16: *
17: * You should have received a copy of the GNU Lesser General Public
18: * License along with this software; if not, write to the Free
19: * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21: */
22: package org.jboss.ha.singleton;
23:
24: import org.jboss.ha.jmx.HAServiceMBean;
25:
26: /**
27: * HA-Singleton interface.
28: * Only one mbean is active at any point in time, cluster-wide.
29: * <p>
30: * The service provides a simple way for a concrete mbean to detect whether
31: * or not it is the active one in the cluster.
32: * <p>
33: * Concrete mbeans would usually do activities like regular clean up of database tables
34: * or saving statistics about cluster usage.
35: *
36: * @author <a href="mailto:ivelin@apache.org">Ivelin Ivanov</a>
37: * @author <a href="mailto:dimitris@jboss.org">Dimitris Andreadis</a>
38: * @version $Revision: 57188 $
39: */
40: public interface HASingletonMBean extends HAServiceMBean {
41: // Constants -----------------------------------------------------
42:
43: /** Notifications emitted locally by an HASingleton to indicate state transitions */
44: String HASINGLETON_STARTING_NOTIFICATION = "org.jboss.ha.singleton.starting";
45: String HASINGLETON_STARTED_NOTIFICATION = "org.jboss.ha.singleton.started";
46: String HASINGLETON_STOPPING_NOTIFICATION = "org.jboss.ha.singleton.stopping";
47: String HASINGLETON_STOPPED_NOTIFICATION = "org.jboss.ha.singleton.stopped";
48:
49: // Attributes ----------------------------------------------------
50:
51: /** True if this cluster node has the active mbean singleton, false otherwise */
52: boolean isMasterNode();
53:
54: }
|