/**
* Copyright 2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.katta.master;
import java.util.Collection;
import java.util.List;
import java.util.UUID;
import net.sf.katta.operation.master.CheckIndicesOperation;
import net.sf.katta.operation.master.RemoveObsoleteShardsOperation;
import net.sf.katta.protocol.ConnectedComponent;
import net.sf.katta.protocol.IAddRemoveListener;
import net.sf.katta.protocol.InteractionProtocol;
import net.sf.katta.protocol.MasterQueue;
import net.sf.katta.protocol.metadata.Version;
import net.sf.katta.protocol.upgrade.UpgradeAction;
import net.sf.katta.protocol.upgrade.UpgradeRegistry;
import net.sf.katta.util.KattaException;
import net.sf.katta.util.MasterConfiguration;
import net.sf.katta.util.ZkConfiguration.PathDef;
import org.I0Itec.zkclient.NetworkUtil;
import org.I0Itec.zkclient.ZkServer;
import org.apache.log4j.Logger;
import com.google.common.base.Preconditions;
public class Master implements ConnectedComponent {
protected final static Logger LOG = Logger.getLogger(Master.class);
protected volatile OperatorThread _operatorThread;
private String _masterName;
private ZkServer _zkServer;
private boolean _shutdownClient;
protected InteractionProtocol _protocol;
private IDeployPolicy _deployPolicy;
private long _safeModeMaxTime;
public Master(InteractionProtocol interactionProtocol, ZkServer zkServer) throws KattaException {
this(interactionProtocol, false);
_zkServer = zkServer;
}
public Master(InteractionProtocol interactionProtocol, boolean shutdownClient) throws KattaException {
this(interactionProtocol, shutdownClient, new MasterConfiguration());
}
@SuppressWarnings("unchecked")
public Master(InteractionProtocol protocol, boolean shutdownClient, MasterConfiguration masterConfiguration)
throws KattaException {
_protocol = protocol;
_masterName = NetworkUtil.getLocalhostName() + "_" + UUID.randomUUID().toString();
_shutdownClient = shutdownClient;
protocol.registerComponent(this);
final String deployPolicyClassName = masterConfiguration.getDeployPolicy();
try {
final Class<IDeployPolicy> policyClazz = (Class<IDeployPolicy>) Class.forName(deployPolicyClassName);
_deployPolicy = policyClazz.newInstance();
} catch (final Exception e) {
throw new KattaException("Unable to instantiate deploy policy", e);
}
_safeModeMaxTime = masterConfiguration.getInt(MasterConfiguration.SAFE_MODE_MAX_TIME);
}
public synchronized void start() {
Preconditions.checkState(!isShutdown(), "master was already shut-down");
becomePrimaryOrSecondaryMaster();
}
@Override
public synchronized void reconnect() {
disconnect();// just to be sure we do not open a 2nd operator thread
becomePrimaryOrSecondaryMaster();
}
@Override
public synchronized void disconnect() {
if (isMaster()) {
_operatorThread.interrupt();
try {
_operatorThread.join();
} catch (InterruptedException e) {
Thread.interrupted();
// proceed
}
_operatorThread = null;
}
}
private synchronized void becomePrimaryOrSecondaryMaster() {
if (isShutdown()) {
return;
}
MasterQueue queue = _protocol.publishMaster(this);
if (queue != null) {
UpgradeAction upgradeAction = UpgradeRegistry.findUpgradeAction(_protocol, Version.readFromJar());
if (upgradeAction != null) {
upgradeAction.upgrade(_protocol);
}
_protocol.setVersion(Version.readFromJar());
LOG.info(getMasterName() + " became master with " + queue.size() + " waiting master operations");
startNodeManagement();
MasterContext masterContext = new MasterContext(_protocol, this, _deployPolicy, queue);
_operatorThread = new OperatorThread(masterContext, _safeModeMaxTime);
_operatorThread.start();
}
}
public synchronized boolean isInSafeMode() {
if (!isMaster()) {
return true;
}
return _operatorThread.isInSafeMode();
}
public Collection<String> getConnectedNodes() {
return _protocol.getLiveNodes();
}
public synchronized MasterContext getContext() {
if (!isMaster()) {
return null;
}
return _operatorThread.getContext();
}
public synchronized boolean isMaster() {
return _operatorThread != null;
}
private synchronized boolean isShutdown() {
return _protocol == null;
}
public String getMasterName() {
return _masterName;
}
public void handleMasterDisappearedEvent() {
becomePrimaryOrSecondaryMaster();
}
private void startNodeManagement() {
LOG.info("start managing nodes...");
List<String> nodes = _protocol.registerChildListener(this, PathDef.NODES_LIVE, new IAddRemoveListener() {
@Override
public void removed(String name) {
synchronized (Master.this) {
if (!isInSafeMode()) {
_protocol.addMasterOperation(new CheckIndicesOperation());
}
}
}
@Override
public void added(String name) {
synchronized (Master.this) {
if (!isMaster()) {
return;
}
_protocol.addMasterOperation(new RemoveObsoleteShardsOperation(name));
if (!isInSafeMode()) {
_protocol.addMasterOperation(new CheckIndicesOperation());
}
}
}
});
_protocol.addMasterOperation(new CheckIndicesOperation());
for (String node : nodes) {
_protocol.addMasterOperation(new RemoveObsoleteShardsOperation(node));
}
LOG.info("found following nodes connected: " + nodes);
}
public synchronized void shutdown() {
if (_protocol != null) {
_protocol.unregisterComponent(this);
if (isMaster()) {
_operatorThread.interrupt();
try {
_operatorThread.join();
_operatorThread = null;
} catch (final InterruptedException e1) {
// proceed
}
}
if (_shutdownClient) {
_protocol.disconnect();
}
_protocol = null;
if (_zkServer != null) {
_zkServer.shutdown();
}
}
}
}