/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.zookeeper.server.quorum;
import org.apache.zookeeper.KeeperException.SessionExpiredException;
import org.apache.zookeeper.jmx.MBeanRegistry;
import org.apache.zookeeper.server.ContainerManager;
import org.apache.zookeeper.server.DataTreeBean;
import org.apache.zookeeper.server.FinalRequestProcessor;
import org.apache.zookeeper.server.PrepRequestProcessor;
import org.apache.zookeeper.server.Request;
import org.apache.zookeeper.server.RequestProcessor;
import org.apache.zookeeper.server.ServerCnxn;
import org.apache.zookeeper.server.ZKDatabase;
import org.apache.zookeeper.server.persistence.FileTxnSnapLog;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
/**
*
* Just like the standard ZooKeeperServer. We just replace the request
* processors: PrepRequestProcessor -> ProposalRequestProcessor ->
* CommitProcessor -> Leader.ToBeAppliedRequestProcessor ->
* FinalRequestProcessor
*/
public class LeaderZooKeeperServer extends QuorumZooKeeperServer {
private ContainerManager containerManager; // guarded by sync
CommitProcessor commitProcessor;
PrepRequestProcessor prepRequestProcessor;
/**
* @param port
* @param dataDir
* @throws IOException
*/
LeaderZooKeeperServer(FileTxnSnapLog logFactory, QuorumPeer self, ZKDatabase zkDb) throws IOException {
super(logFactory, self.tickTime, self.minSessionTimeout, self.maxSessionTimeout, zkDb, self);
}
public Leader getLeader(){
return self.leader;
}
@Override
protected void setupRequestProcessors() {
RequestProcessor finalProcessor = new FinalRequestProcessor(this);
RequestProcessor toBeAppliedProcessor = new Leader.ToBeAppliedRequestProcessor(finalProcessor, getLeader());
commitProcessor = new CommitProcessor(toBeAppliedProcessor,
Long.toString(getServerId()), false,
getZooKeeperServerListener());
commitProcessor.start();
ProposalRequestProcessor proposalProcessor = new ProposalRequestProcessor(this,
commitProcessor);
proposalProcessor.initialize();
prepRequestProcessor = new PrepRequestProcessor(this, proposalProcessor);
prepRequestProcessor.start();
firstProcessor = new LeaderRequestProcessor(this, prepRequestProcessor);
setupContainerManager();
}
private synchronized void setupContainerManager() {
containerManager = new ContainerManager(getZKDatabase(), prepRequestProcessor,
Integer.getInteger("znode.container.checkIntervalMs", (int) TimeUnit.MINUTES.toMillis(1)),
Integer.getInteger("znode.container.maxPerMinute", 10000)
);
}
@Override
public synchronized void startup() {
super.startup();
if (containerManager != null) {
containerManager.start();
}
}
@Override
public synchronized void shutdown() {
if (containerManager != null) {
containerManager.stop();
}
super.shutdown();
}
@Override
public int getGlobalOutstandingLimit() {
int divisor = self.getQuorumSize() > 2 ? self.getQuorumSize() - 1 : 1;
return super.getGlobalOutstandingLimit() / divisor;
}
@Override
public void createSessionTracker() {
sessionTracker = new LeaderSessionTracker(
this, getZKDatabase().getSessionWithTimeOuts(),
tickTime, self.getId(), self.areLocalSessionsEnabled(),
getZooKeeperServerListener());
}
public boolean touch(long sess, int to) {
return sessionTracker.touchSession(sess, to);
}
public boolean checkIfValidGlobalSession(long sess, int to) {
if (self.areLocalSessionsEnabled() &&
!upgradeableSessionTracker.isGlobalSession(sess)) {
return false;
}
return sessionTracker.touchSession(sess, to);
}
/**
* Requests coming from the learner should go directly to
* PrepRequestProcessor
*
* @param request
*/
public void submitLearnerRequest(Request request) {
/*
* Requests coming from the learner should have gone through
* submitRequest() on each server which already perform some request
* validation, so we don't need to do it again.
*
* Additionally, LearnerHandler should start submitting requests into
* the leader's pipeline only when the leader's server is started, so we
* can submit the request directly into PrepRequestProcessor.
*
* This is done so that requests from learners won't go through
* LeaderRequestProcessor which perform local session upgrade.
*/
prepRequestProcessor.processRequest(request);
}
@Override
protected void registerJMX() {
// register with JMX
try {
jmxDataTreeBean = new DataTreeBean(getZKDatabase().getDataTree());
MBeanRegistry.getInstance().register(jmxDataTreeBean, jmxServerBean);
} catch (Exception e) {
LOG.warn("Failed to register with JMX", e);
jmxDataTreeBean = null;
}
}
public void registerJMX(LeaderBean leaderBean,
LocalPeerBean localPeerBean)
{
// register with JMX
if (self.jmxLeaderElectionBean != null) {
try {
MBeanRegistry.getInstance().unregister(self.jmxLeaderElectionBean);
} catch (Exception e) {
LOG.warn("Failed to register with JMX", e);
}
self.jmxLeaderElectionBean = null;
}
try {
jmxServerBean = leaderBean;
MBeanRegistry.getInstance().register(leaderBean, localPeerBean);
} catch (Exception e) {
LOG.warn("Failed to register with JMX", e);
jmxServerBean = null;
}
}
@Override
protected void unregisterJMX() {
// unregister from JMX
try {
if (jmxDataTreeBean != null) {
MBeanRegistry.getInstance().unregister(jmxDataTreeBean);
}
} catch (Exception e) {
LOG.warn("Failed to unregister with JMX", e);
}
jmxDataTreeBean = null;
}
protected void unregisterJMX(Leader leader) {
// unregister from JMX
try {
if (jmxServerBean != null) {
MBeanRegistry.getInstance().unregister(jmxServerBean);
}
} catch (Exception e) {
LOG.warn("Failed to unregister with JMX", e);
}
jmxServerBean = null;
}
@Override
public String getState() {
return "leader";
}
/**
* Returns the id of the associated QuorumPeer, which will do for a unique
* id of this server.
*/
@Override
public long getServerId() {
return self.getId();
}
@Override
protected void revalidateSession(ServerCnxn cnxn, long sessionId,
int sessionTimeout) throws IOException {
super.revalidateSession(cnxn, sessionId, sessionTimeout);
try {
// setowner as the leader itself, unless updated
// via the follower handlers
setOwner(sessionId, ServerCnxn.me);
} catch (SessionExpiredException e) {
// this is ok, it just means that the session revalidation failed.
}
}
}