/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002-2010 Oracle. All rights reserved.
*
*/
package com.sleepycat.je.rep.stream;
import java.net.InetSocketAddress;
import java.util.logging.Logger;
import com.sleepycat.je.rep.elections.Learner;
import com.sleepycat.je.rep.elections.MasterValue;
import com.sleepycat.je.rep.elections.Proposer.Proposal;
import com.sleepycat.je.rep.elections.Protocol.Value;
import com.sleepycat.je.rep.impl.node.RepNode;
import com.sleepycat.je.utilint.LoggerUtils;
/**
* The Listener registered with Elections to learn about new Masters
*/
public class MasterChangeListener implements Learner.Listener {
/* The Value that is "current" for this Node. */
private Value currentValue = null;
private final RepNode repNode;
private final Logger logger;
public MasterChangeListener(RepNode repNode) {
this.repNode = repNode;
logger = LoggerUtils.getLogger(getClass());
}
/**
* Implements the Listener protocol. The method should not have any
* operations that might wait, since notifications are single threaded.
*/
public void notify(Proposal proposal, Value value) {
try {
repNode.getVLSNFreezeLatch().vlsnEvent(proposal);
/* We have a new proposal, is it truly different? */
if (value.equals(currentValue)) {
LoggerUtils.fine(logger, repNode.getRepImpl(),
"Master change listener -- no value change." +
"Proposal: " + proposal + " Value: " + value);
return;
}
MasterValue masterValue = ((MasterValue) value);
LoggerUtils.fine(logger, repNode.getRepImpl(),
"Master change listener notified. Proposal:" +
proposal + " Value: " + value);
LoggerUtils.info(logger, repNode.getRepImpl(),
"Master changed to " +
masterValue.getNameId().getName());
repNode.getMasterStatus().setGroupMaster
(new InetSocketAddress(masterValue.getHostName(),
masterValue.getPort()),
masterValue.getNameId());
/* Propagate the information to any monitors. */
repNode.getElections().asyncInformMonitors(proposal, value);
} finally {
currentValue = value;
}
}
}