/**
* Copyright (C) 2010-2013 Alibaba Group Holding Limited
*
* 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 com.alibaba.rocketmq.remoting.netty;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alibaba.rocketmq.remoting.ChannelEventListener;
import com.alibaba.rocketmq.remoting.InvokeCallback;
import com.alibaba.rocketmq.remoting.RPCHook;
import com.alibaba.rocketmq.remoting.common.Pair;
import com.alibaba.rocketmq.remoting.common.RemotingHelper;
import com.alibaba.rocketmq.remoting.common.SemaphoreReleaseOnlyOnce;
import com.alibaba.rocketmq.remoting.common.ServiceThread;
import com.alibaba.rocketmq.remoting.exception.RemotingSendRequestException;
import com.alibaba.rocketmq.remoting.exception.RemotingTimeoutException;
import com.alibaba.rocketmq.remoting.exception.RemotingTooMuchRequestException;
import com.alibaba.rocketmq.remoting.protocol.RemotingCommand;
import com.alibaba.rocketmq.remoting.protocol.RemotingSysResponseCode;
/**
* Server与Client公用抽象类
*
* @author shijia.wxr<vintage.wang@gmail.com>
* @since 2013-7-13
*/
public abstract class NettyRemotingAbstract {
private static final Logger plog = LoggerFactory.getLogger(RemotingHelper.RemotingLogName);
// 信号量，Oneway情况会使用，防止本地Netty缓存请求过多
protected final Semaphore semaphoreOneway;
// 信号量，异步调用情况会使用，防止本地Netty缓存请求过多
protected final Semaphore semaphoreAsync;
// 缓存所有对外请求
protected final ConcurrentHashMap<Integer /* opaque */, ResponseFuture> responseTable =
new ConcurrentHashMap<Integer, ResponseFuture>(256);
// 默认请求代码处理器
protected Pair<NettyRequestProcessor, ExecutorService> defaultRequestProcessor;
// 注册的各个RPC处理器
protected final HashMap<Integer/* request code */, Pair<NettyRequestProcessor, ExecutorService>> processorTable =
new HashMap<Integer, Pair<NettyRequestProcessor, ExecutorService>>(64);
protected final NettyEventExecuter nettyEventExecuter = new NettyEventExecuter();
public abstract ChannelEventListener getChannelEventListener();
public abstract RPCHook getRPCHook();
public void putNettyEvent(final NettyEvent event) {
this.nettyEventExecuter.putNettyEvent(event);
}
class NettyEventExecuter extends ServiceThread {
private final LinkedBlockingQueue<NettyEvent> eventQueue = new LinkedBlockingQueue<NettyEvent>();
private final int MaxSize = 10000;
public void putNettyEvent(final NettyEvent event) {
if (this.eventQueue.size() <= MaxSize) {
this.eventQueue.add(event);
}
else {
plog.warn("event queue size[{}] enough, so drop this event {}", this.eventQueue.size(),
event.toString());
}
}
@Override
public void run() {
plog.info(this.getServiceName() + " service started");
final ChannelEventListener listener = NettyRemotingAbstract.this.getChannelEventListener();
while (!this.isStoped()) {
try {
NettyEvent event = this.eventQueue.poll(3000, TimeUnit.MILLISECONDS);
if (event != null && listener != null) {
switch (event.getType()) {
case IDLE:
listener.onChannelIdle(event.getRemoteAddr(), event.getChannel());
break;
case CLOSE:
listener.onChannelClose(event.getRemoteAddr(), event.getChannel());
break;
case CONNECT:
listener.onChannelConnect(event.getRemoteAddr(), event.getChannel());
break;
case EXCEPTION:
listener.onChannelException(event.getRemoteAddr(), event.getChannel());
break;
default:
break;
}
}
}
catch (Exception e) {
plog.warn(this.getServiceName() + " service has exception. ", e);
}
}
plog.info(this.getServiceName() + " service end");
}
@Override
public String getServiceName() {
return NettyEventExecuter.class.getSimpleName();
}
}
public NettyRemotingAbstract(final int permitsOneway, final int permitsAsync) {
this.semaphoreOneway = new Semaphore(permitsOneway, true);
this.semaphoreAsync = new Semaphore(permitsAsync, true);
}
public void processRequestCommand(final ChannelHandlerContext ctx, final RemotingCommand cmd) {
final Pair<NettyRequestProcessor, ExecutorService> matched = this.processorTable.get(cmd.getCode());
final Pair<NettyRequestProcessor, ExecutorService> pair =
null == matched ? this.defaultRequestProcessor : matched;
if (pair != null) {
Runnable run = new Runnable() {
@Override
public void run() {
try {
RPCHook rpcHook = NettyRemotingAbstract.this.getRPCHook();
if (rpcHook != null) {
rpcHook
.doBeforeRequest(RemotingHelper.parseChannelRemoteAddr(ctx.channel()), cmd);
}
final RemotingCommand response = pair.getObject1().processRequest(ctx, cmd);
if (rpcHook != null) {
rpcHook.doAfterResponse(cmd, response);
}
// Oneway形式忽略应答结果
if (!cmd.isOnewayRPC()) {
if (response != null) {
response.setOpaque(cmd.getOpaque());
response.markResponseType();
try {
ctx.writeAndFlush(response);
}
catch (Throwable e) {
plog.error("process request over, but response failed", e);
plog.error(cmd.toString());
plog.error(response.toString());
}
}
else {
// 收到请求，但是没有返回应答，可能是processRequest中进行了应答，忽略这种情况
}
}
}
catch (Throwable e) {
plog.error("process request exception", e);
plog.error(cmd.toString());
if (!cmd.isOnewayRPC()) {
final RemotingCommand response =
RemotingCommand.createResponseCommand(
RemotingSysResponseCode.SYSTEM_ERROR,//
RemotingHelper.exceptionSimpleDesc(e));
response.setOpaque(cmd.getOpaque());
ctx.writeAndFlush(response);
}
}
}
};
try {
// 这里需要做流控，要求线程池对应的队列必须是有大小限制的
pair.getObject2().submit(run);
}
catch (RejectedExecutionException e) {
plog.warn(RemotingHelper.parseChannelRemoteAddr(ctx.channel()) //
+ ", too many requests and system thread pool busy, RejectedExecutionException " //
+ pair.getObject2().toString() //
+ " request code: " + cmd.getCode());
if (!cmd.isOnewayRPC()) {
final RemotingCommand response =
RemotingCommand.createResponseCommand(RemotingSysResponseCode.SYSTEM_BUSY,
"too many requests and system thread pool busy, please try another server");
response.setOpaque(cmd.getOpaque());
ctx.writeAndFlush(response);
}
}
}
else {
String error = " request type " + cmd.getCode() + " not supported";
final RemotingCommand response =
RemotingCommand.createResponseCommand(RemotingSysResponseCode.REQUEST_CODE_NOT_SUPPORTED,
error);
response.setOpaque(cmd.getOpaque());
ctx.writeAndFlush(response);
plog.error(RemotingHelper.parseChannelRemoteAddr(ctx.channel()) + error);
}
}
public void processResponseCommand(ChannelHandlerContext ctx, RemotingCommand cmd) {
final ResponseFuture responseFuture = responseTable.get(cmd.getOpaque());
if (responseFuture != null) {
responseFuture.setResponseCommand(cmd);
responseFuture.release();
// 异步调用
if (responseFuture.getInvokeCallback() != null) {
boolean runInThisThread = false;
ExecutorService executor = this.getCallbackExecutor();
if (executor != null) {
try {
executor.submit(new Runnable() {
@Override
public void run() {
try {
responseFuture.executeInvokeCallback();
}
catch (Throwable e) {
plog.warn("excute callback in executor exception, and callback throw", e);
}
}
});
}
catch (Exception e) {
runInThisThread = true;
plog.warn("excute callback in executor exception, maybe executor busy", e);
}
}
else {
runInThisThread = true;
}
if (runInThisThread) {
try {
responseFuture.executeInvokeCallback();
}
catch (Throwable e) {
plog.warn("executeInvokeCallback Exception", e);
}
}
}
// 同步调用
else {
responseFuture.putResponse(cmd);
}
}
else {
plog.warn("receive response, but not matched any request, "
+ RemotingHelper.parseChannelRemoteAddr(ctx.channel()));
plog.warn(cmd.toString());
}
responseTable.remove(cmd.getOpaque());
}
public void processMessageReceived(ChannelHandlerContext ctx, RemotingCommand msg) throws Exception {
final RemotingCommand cmd = msg;
if (cmd != null) {
switch (cmd.getType()) {
case REQUEST_COMMAND:
processRequestCommand(ctx, cmd);
break;
case RESPONSE_COMMAND:
processResponseCommand(ctx, cmd);
break;
default:
break;
}
}
}
abstract public ExecutorService getCallbackExecutor();
public void scanResponseTable() {
Iterator<Entry<Integer, ResponseFuture>> it = this.responseTable.entrySet().iterator();
while (it.hasNext()) {
Entry<Integer, ResponseFuture> next = it.next();
ResponseFuture rep = next.getValue();
if ((rep.getBeginTimestamp() + rep.getTimeoutMillis() + 1000) <= System.currentTimeMillis()) {
it.remove();
try {
rep.executeInvokeCallback();
}
catch (Throwable e) {
plog.warn("scanResponseTable, operationComplete Exception", e);
}
finally {
rep.release();
}
plog.warn("remove timeout request, " + rep);
}
}
}
public RemotingCommand invokeSyncImpl(final Channel channel, final RemotingCommand request,
final long timeoutMillis) throws InterruptedException, RemotingSendRequestException,
RemotingTimeoutException {
try {
final ResponseFuture responseFuture =
new ResponseFuture(request.getOpaque(), timeoutMillis, null, null);
this.responseTable.put(request.getOpaque(), responseFuture);
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f) throws Exception {
if (f.isSuccess()) {
responseFuture.setSendRequestOK(true);
return;
}
else {
responseFuture.setSendRequestOK(false);
}
responseTable.remove(request.getOpaque());
responseFuture.setCause(f.cause());
responseFuture.putResponse(null);
plog.warn("send a request command to channel <" + channel.remoteAddress() + "> failed.");
plog.warn(request.toString());
}
});
RemotingCommand responseCommand = responseFuture.waitResponse(timeoutMillis);
if (null == responseCommand) {
// 发送请求成功，读取应答超时
if (responseFuture.isSendRequestOK()) {
throw new RemotingTimeoutException(RemotingHelper.parseChannelRemoteAddr(channel),
timeoutMillis, responseFuture.getCause());
}
// 发送请求失败
else {
throw new RemotingSendRequestException(RemotingHelper.parseChannelRemoteAddr(channel),
responseFuture.getCause());
}
}
return responseCommand;
}
finally {
this.responseTable.remove(request.getOpaque());
}
}
public void invokeAsyncImpl(final Channel channel, final RemotingCommand request,
final long timeoutMillis, final InvokeCallback invokeCallback) throws InterruptedException,
RemotingTooMuchRequestException, RemotingTimeoutException, RemotingSendRequestException {
boolean acquired = this.semaphoreAsync.tryAcquire(timeoutMillis, TimeUnit.MILLISECONDS);
if (acquired) {
final SemaphoreReleaseOnlyOnce once = new SemaphoreReleaseOnlyOnce(this.semaphoreAsync);
final ResponseFuture responseFuture =
new ResponseFuture(request.getOpaque(), timeoutMillis, invokeCallback, once);
this.responseTable.put(request.getOpaque(), responseFuture);
try {
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f) throws Exception {
if (f.isSuccess()) {
responseFuture.setSendRequestOK(true);
return;
}
else {
responseFuture.setSendRequestOK(false);
}
responseFuture.putResponse(null);
responseTable.remove(request.getOpaque());
try {
responseFuture.executeInvokeCallback();
}
catch (Throwable e) {
plog.warn("excute callback in writeAndFlush addListener, and callback throw", e);
}
finally {
responseFuture.release();
}
plog.warn("send a request command to channel <{}> failed.",
RemotingHelper.parseChannelRemoteAddr(channel));
plog.warn(request.toString());
}
});
}
catch (Exception e) {
responseFuture.release();
plog.warn(
"send a request command to channel <" + RemotingHelper.parseChannelRemoteAddr(channel)
+ "> Exception", e);
throw new RemotingSendRequestException(RemotingHelper.parseChannelRemoteAddr(channel), e);
}
}
else {
if (timeoutMillis <= 0) {
throw new RemotingTooMuchRequestException("invokeAsyncImpl invoke too fast");
}
else {
String info =
String
.format(
"invokeAsyncImpl tryAcquire semaphore timeout, %dms, waiting thread nums: %d semaphoreAsyncValue: %d", //
timeoutMillis,//
this.semaphoreAsync.getQueueLength(),//
this.semaphoreAsync.availablePermits()//
);
plog.warn(info);
plog.warn(request.toString());
throw new RemotingTimeoutException(info);
}
}
}
public void invokeOnewayImpl(final Channel channel, final RemotingCommand request,
final long timeoutMillis) throws InterruptedException, RemotingTooMuchRequestException,
RemotingTimeoutException, RemotingSendRequestException {
request.markOnewayRPC();
boolean acquired = this.semaphoreOneway.tryAcquire(timeoutMillis, TimeUnit.MILLISECONDS);
if (acquired) {
final SemaphoreReleaseOnlyOnce once = new SemaphoreReleaseOnlyOnce(this.semaphoreOneway);
try {
channel.writeAndFlush(request).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture f) throws Exception {
once.release();
if (!f.isSuccess()) {
plog.warn("send a request command to channel <" + channel.remoteAddress()
+ "> failed.");
plog.warn(request.toString());
}
}
});
}
catch (Exception e) {
once.release();
plog.warn("write send a request command to channel <" + channel.remoteAddress() + "> failed.");
throw new RemotingSendRequestException(RemotingHelper.parseChannelRemoteAddr(channel), e);
}
}
else {
if (timeoutMillis <= 0) {
throw new RemotingTooMuchRequestException("invokeOnewayImpl invoke too fast");
}
else {
String info =
String
.format(
"invokeOnewayImpl tryAcquire semaphore timeout, %dms, waiting thread nums: %d semaphoreAsyncValue: %d", //
timeoutMillis,//
this.semaphoreAsync.getQueueLength(),//
this.semaphoreAsync.availablePermits()//
);
plog.warn(info);
plog.warn(request.toString());
throw new RemotingTimeoutException(info);
}
}
}
}