/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*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.rubyeye.xmemcached.impl;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import net.rubyeye.xmemcached.MemcachedClient;
import net.rubyeye.xmemcached.MemcachedClientStateListener;
import net.rubyeye.xmemcached.auth.AuthMemcachedConnectListener;
import net.rubyeye.xmemcached.command.Command;
import net.rubyeye.xmemcached.command.CommandType;
import net.rubyeye.xmemcached.command.MapReturnValueAware;
import net.rubyeye.xmemcached.command.OperationStatus;
import net.rubyeye.xmemcached.command.StoreCommand;
import net.rubyeye.xmemcached.command.binary.BinaryGetCommand;
import net.rubyeye.xmemcached.command.binary.BinaryVersionCommand;
import net.rubyeye.xmemcached.command.text.TextGetOneCommand;
import net.rubyeye.xmemcached.command.text.TextVersionCommand;
import net.rubyeye.xmemcached.monitor.StatisticsHandler;
import net.rubyeye.xmemcached.networking.MemcachedSession;
import net.rubyeye.xmemcached.networking.MemcachedSessionConnectListener;
import net.rubyeye.xmemcached.transcoders.CachedData;
import net.rubyeye.xmemcached.utils.InetSocketAddressWrapper;
import net.rubyeye.xmemcached.utils.Protocol;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.code.yanf4j.buffer.IoBuffer;
import com.google.code.yanf4j.core.Session;
import com.google.code.yanf4j.core.impl.AbstractSession;
import com.google.code.yanf4j.core.impl.HandlerAdapter;
import com.google.code.yanf4j.util.SystemUtils;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
/**
* Memcached Session Handler,used for dispatching commands and session's
* lifecycle management
*
* @author dennis
*
*/
public class MemcachedHandler extends HandlerAdapter {
private static final int MAX_HEARTBEAT_THREADS = Integer.parseInt(System
.getProperty("xmemcached.heartbeat.max_threads",
String.valueOf(SystemUtils.getSystemThreadCount())));
private final StatisticsHandler statisticsHandler;
private ExecutorService heartBeatThreadPool;
private final MemcachedSessionConnectListener listener;
private final MemcachedClient client;
private static final Logger log = LoggerFactory
.getLogger(MemcachedHandler.class);
/**
* On receive message from memcached server
*/
@Override
public final void onMessageReceived(final Session session, final Object msg) {
Command command = (Command) msg;
if (this.statisticsHandler.isStatistics()) {
if (command.getCopiedMergeCount() > 0
&& command instanceof MapReturnValueAware) {
Map<String, CachedData> returnValues = ((MapReturnValueAware) command)
.getReturnValues();
int size = returnValues.size();
this.statisticsHandler.statistics(CommandType.GET_HIT, size);
this.statisticsHandler.statistics(CommandType.GET_MISS,
command.getCopiedMergeCount() - size);
} else if (command instanceof TextGetOneCommand
|| command instanceof BinaryGetCommand) {
if (command.getResult() != null) {
this.statisticsHandler.statistics(CommandType.GET_HIT);
} else {
this.statisticsHandler.statistics(CommandType.GET_MISS);
}
} else {
if (command.getCopiedMergeCount() > 0) {
this.statisticsHandler.statistics(command.getCommandType(),
command.getCopiedMergeCount());
} else
this.statisticsHandler.statistics(command.getCommandType());
}
}
}
private volatile boolean enableHeartBeat = true;
public void setEnableHeartBeat(boolean enableHeartBeat) {
this.enableHeartBeat = enableHeartBeat;
}
public static final IoBuffer EMPTY_BUF = IoBuffer.allocate(0);
/**
* put command which have been sent to queue
*/
@Override
public final void onMessageSent(Session session, Object msg) {
Command command = (Command) msg;
command.setStatus(OperationStatus.SENT);
// After message sent,we can set the buffer to be null for gc friendly.
command.setIoBuffer(EMPTY_BUF);
switch (command.getCommandType()) {
case ADD:
case APPEND:
case SET:
case SET_MANY:
// After message sent,we can set the value to be null for gc
// friendly.
if (command instanceof StoreCommand) {
((StoreCommand) command).setValue(null);
}
break;
}
}
@Override
public void onExceptionCaught(Session session, Throwable throwable) {
log.error("XMemcached network layout exception", throwable);
}
/**
* On session started
*/
@Override
public void onSessionStarted(Session session) {
session.setUseBlockingRead(true);
session.setAttribute(HEART_BEAT_FAIL_COUNT_ATTR, new AtomicInteger(0));
for (MemcachedClientStateListener listener : this.client
.getStateListeners()) {
listener.onConnected(this.client, session.getRemoteSocketAddress());
}
this.listener.onConnect((MemcachedTCPSession) session, this.client);
}
/**
* Check if have to reconnect on session closed
*/
@Override
public final void onSessionClosed(Session session) {
this.client.getConnector().removeSession(session);
// Clear write queue to release noreply operations.
((AbstractSession) session).clearWriteQueue();
MemcachedTCPSession memcachedSession = (MemcachedTCPSession) session;
// destroy memached session
memcachedSession.destroy();
if (this.client.getConnector().isStarted()
&& memcachedSession.isAllowReconnect()) {
this.reconnect(memcachedSession);
}
for (MemcachedClientStateListener listener : this.client
.getStateListeners()) {
listener.onDisconnected(this.client,
session.getRemoteSocketAddress());
}
}
/**
* Do a heartbeat action
*/
@Override
public void onSessionIdle(Session session) {
checkHeartBeat(session);
}
private void checkHeartBeat(Session session) {
if (this.enableHeartBeat) {
log.debug(
"Check session ({}) is alive,send heartbeat",
session.getRemoteSocketAddress() == null ? "unknown"
: SystemUtils.getRawAddress(session
.getRemoteSocketAddress())
+ ":"
+ session.getRemoteSocketAddress()
.getPort());
Command versionCommand = null;
CountDownLatch latch = new CountDownLatch(1);
if (this.client.getProtocol() == Protocol.Binary) {
versionCommand = new BinaryVersionCommand(latch,
session.getRemoteSocketAddress());
} else {
versionCommand = new TextVersionCommand(latch,
session.getRemoteSocketAddress());
}
session.write(versionCommand);
// Start a check thread,avoid blocking reactor thread
if (this.heartBeatThreadPool != null) {
this.heartBeatThreadPool.execute(new CheckHeartResultThread(
versionCommand, session));
}
}
}
private static final String HEART_BEAT_FAIL_COUNT_ATTR = "heartBeatFailCount";
private static final int MAX_HEART_BEAT_FAIL_COUNT = Integer
.parseInt(System.getProperty("xmemcached.heartbeat.max.fail.times",
"3"));
final static class CheckHeartResultThread implements Runnable {
private final Command versionCommand;
private final Session session;
public CheckHeartResultThread(Command versionCommand, Session session) {
super();
this.versionCommand = versionCommand;
this.session = session;
}
public void run() {
try {
AtomicInteger heartBeatFailCount = (AtomicInteger) this.session
.getAttribute(HEART_BEAT_FAIL_COUNT_ATTR);
if (heartBeatFailCount != null) {
if (!this.versionCommand.getLatch().await(2000,
TimeUnit.MILLISECONDS)) {
heartBeatFailCount.incrementAndGet();
} else {
if (this.versionCommand.getResult() == null) {
heartBeatFailCount.incrementAndGet();
} else {
// reset the failure counter
heartBeatFailCount.set(0);
}
}
if (heartBeatFailCount.get() > MAX_HEART_BEAT_FAIL_COUNT) {
log.warn("Session("
+ SystemUtils.getRawAddress(this.session
.getRemoteSocketAddress())
+ ":"
+ this.session.getRemoteSocketAddress()
.getPort() + ") heartbeat fail "
+ heartBeatFailCount.get()
+ " times,close session and try to heal it");
this.session.close();// close session
heartBeatFailCount.set(0);
}
}
} catch (InterruptedException e) {
// ignore
}
}
}
/**
* Auto reconect to memcached server
*
* @param session
*/
protected void reconnect(MemcachedTCPSession session) {
if (!this.client.isShutdown()) {
// Prevent reconnecting repeatedly
synchronized (session) {
if (!session.isAllowReconnect()) {
return;
}
session.setAllowReconnect(false);
}
MemcachedSession memcachedTCPSession = session;
InetSocketAddressWrapper inetSocketAddressWrapper = memcachedTCPSession
.getInetSocketAddressWrapper();
this.client.getConnector().addToWatingQueue(
new ReconnectRequest(inetSocketAddressWrapper, 0,
this.client.getHealSessionInterval()));
}
}
public void stop() {
this.heartBeatThreadPool.shutdown();
}
final long HEARTBEAT_PERIOD = Long.parseLong(System.getProperty(
"xmemcached.heartbeat.period", "5000"));
public void start() {
final String name = "XMemcached-HeartBeatPool[" + client.getName()
+ "]";
final AtomicInteger threadCounter = new AtomicInteger();
long keepAliveTime = client.getConnector().getSessionIdleTimeout() * 3 / 2;
this.heartBeatThreadPool = new ThreadPoolExecutor(1,
MAX_HEARTBEAT_THREADS, keepAliveTime, TimeUnit.MILLISECONDS,
new SynchronousQueue<Runnable>(), new ThreadFactory() {
public Thread newThread(Runnable r) {
Thread t = new Thread(r, name + "-"
+ threadCounter.getAndIncrement());
t.setDaemon(true);
if (t.getPriority() != Thread.NORM_PRIORITY) {
t.setPriority(Thread.NORM_PRIORITY);
}
return t;
}
}, new ThreadPoolExecutor.DiscardPolicy());
}
public MemcachedHandler(MemcachedClient client) {
super();
this.client = client;
this.listener = new AuthMemcachedConnectListener();
this.statisticsHandler = new StatisticsHandler();
}
}