/**
* 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.broker.processor;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.FileRegion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alibaba.rocketmq.broker.BrokerController;
import com.alibaba.rocketmq.broker.client.ConsumerGroupInfo;
import com.alibaba.rocketmq.broker.digestlog.PullmsgLiveMoniter;
import com.alibaba.rocketmq.broker.longpolling.PullRequest;
import com.alibaba.rocketmq.broker.pagecache.ManyMessageTransfer;
import com.alibaba.rocketmq.common.TopicConfig;
import com.alibaba.rocketmq.common.constant.LoggerName;
import com.alibaba.rocketmq.common.constant.PermName;
import com.alibaba.rocketmq.common.filter.FilterAPI;
import com.alibaba.rocketmq.common.help.FAQUrl;
import com.alibaba.rocketmq.common.protocol.MQProtos.MQResponseCode;
import com.alibaba.rocketmq.common.protocol.header.PullMessageRequestHeader;
import com.alibaba.rocketmq.common.protocol.header.PullMessageResponseHeader;
import com.alibaba.rocketmq.common.protocol.heartbeat.MessageModel;
import com.alibaba.rocketmq.common.protocol.heartbeat.SubscriptionData;
import com.alibaba.rocketmq.common.subscription.SubscriptionGroupConfig;
import com.alibaba.rocketmq.common.sysflag.PullSysFlag;
import com.alibaba.rocketmq.remoting.common.RemotingHelper;
import com.alibaba.rocketmq.remoting.exception.RemotingCommandException;
import com.alibaba.rocketmq.remoting.netty.NettyRequestProcessor;
import com.alibaba.rocketmq.remoting.protocol.RemotingCommand;
import com.alibaba.rocketmq.remoting.protocol.RemotingProtos.ResponseCode;
import com.alibaba.rocketmq.store.GetMessageResult;
import com.alibaba.rocketmq.store.config.BrokerRole;
/**
* 拉消息请求处理
*
* @author shijia.wxr<vintage.wang@gmail.com>
* @since 2013-7-26
*/
public class PullMessageProcessor implements NettyRequestProcessor {
private static final Logger log = LoggerFactory.getLogger(LoggerName.BrokerLoggerName);
private final BrokerController brokerController;
public PullMessageProcessor(final BrokerController brokerController) {
this.brokerController = brokerController;
}
@Override
public RemotingCommand processRequest(final ChannelHandlerContext ctx, RemotingCommand request)
throws RemotingCommandException {
return this.processRequest(ctx.channel(), request, true);
}
public void excuteRequestWhenWakeup(final Channel channel, final RemotingCommand request)
throws RemotingCommandException {
Runnable run = new Runnable() {
@Override
public void run() {
try {
/*
* chen.si 此次不会再挂起了，一定会返回
*/
final RemotingCommand response =
PullMessageProcessor.this.processRequest(channel, request, false);
if (response != null) {
response.setOpaque(request.getOpaque());
response.markResponseType();
try {
channel.writeAndFlush(response).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
log.error("processRequestWrapper response to "
+ future.channel().remoteAddress() + " failed",
future.cause());
log.error(request.toString());
log.error(response.toString());
}
}
});
}
catch (Throwable e) {
log.error("processRequestWrapper process request over, but response failed", e);
log.error(request.toString());
log.error(response.toString());
}
}
}
catch (RemotingCommandException e1) {
log.error("excuteRequestWhenWakeup run", e1);
}
}
};
/*
* chen.si 避免阻塞 接收producer请求而存储消息 的线程。 扔到线程池中处理
*/
this.brokerController.getPullMessageExecutor().submit(run);
}
private RemotingCommand processRequest(final Channel channel, RemotingCommand request,
boolean brokerAllowSuspend) throws RemotingCommandException {
/**
* chen.si 收到消息拉取请求
*/
RemotingCommand response = RemotingCommand.createResponseCommand(PullMessageResponseHeader.class);
final PullMessageResponseHeader responseHeader =
(PullMessageResponseHeader) response.getCustomHeader();
final PullMessageRequestHeader requestHeader =
(PullMessageRequestHeader) request.decodeCommandCustomHeader(PullMessageRequestHeader.class);
/**
* chen.si TODO 需要看一下，这里是什么意思，哪里使用了sendfile system call
*/
// 由于使用sendfile，所以必须要设置
response.setOpaque(request.getOpaque());
if (log.isDebugEnabled()) {
log.debug("receive PullMessage request command, " + request);
}
// 检查Broker权限
if (!PermName.isReadable(this.brokerController.getBrokerConfig().getBrokerPermission())) {
response.setCode(MQResponseCode.NO_PERMISSION_VALUE);
response.setRemark("the broker[" + this.brokerController.getBrokerConfig().getBrokerIP1()
+ "] pulling message is forbidden");
return response;
}
/**
* chen.si consumer group相关的信息判断
*
* 1. consumer group是否属于 配置的group列表
* 2. 如果consumer group不在配置列表中，则根据broker的配置autoCreateSubscriptionGroup=true是否自动创建
*/
// 确保订阅组存在
SubscriptionGroupConfig subscriptionGroupConfig =
this.brokerController.getSubscriptionGroupManager().findSubscriptionGroupConfig(
requestHeader.getConsumerGroup());
if (null == subscriptionGroupConfig) {
response.setCode(MQResponseCode.SUBSCRIPTION_GROUP_NOT_EXIST_VALUE);
response.setRemark("subscription group not exist, " + requestHeader.getConsumerGroup() + " "
+ FAQUrl.suggestTodo(FAQUrl.SUBSCRIPTION_GROUP_NOT_EXIST));
return response;
}
/**
* chen.si consumer group是否允许消费
*/
// 这个订阅组是否可以消费消息
if (!subscriptionGroupConfig.isConsumeEnable()) {
response.setCode(MQResponseCode.NO_PERMISSION_VALUE);
response.setRemark("subscription group no permission, " + requestHeader.getConsumerGroup());
return response;
}
final boolean hasSuspendFlag = PullSysFlag.hasSuspendFlag(requestHeader.getSysFlag());
final boolean hasCommitOffsetFlag = PullSysFlag.hasCommitOffsetFlag(requestHeader.getSysFlag());
final boolean hasSubscriptionFlag = PullSysFlag.hasSubscriptionFlag(requestHeader.getSysFlag());
/**
* chen.si 获取无消息的hang时长
*/
final long suspendTimeoutMillisLong = hasSuspendFlag ? requestHeader.getSuspendTimeoutMillis() : 0;
// 检查topic是否存在
TopicConfig topicConfig =
this.brokerController.getTopicConfigManager().selectTopicConfig(requestHeader.getTopic());
if (null == topicConfig) {
log.error("the topic " + requestHeader.getTopic() + " not exist, consumer: "
+ RemotingHelper.parseChannelRemoteAddr(channel));
response.setCode(MQResponseCode.TOPIC_NOT_EXIST_VALUE);
response.setRemark("topic[" + requestHeader.getTopic() + "] not exist, apply first please!"
+ FAQUrl.suggestTodo(FAQUrl.APPLY_TOPIC_URL));
return response;
}
// 检查topic权限
if (!PermName.isReadable(topicConfig.getPerm())) {
response.setCode(MQResponseCode.NO_PERMISSION_VALUE);
response.setRemark("the topic[" + requestHeader.getTopic() + "] pulling message is forbidden");
return response;
}
// 检查队列有效性
if (requestHeader.getQueueId() < 0 || requestHeader.getQueueId() >= topicConfig.getReadQueueNums()) {
String errorInfo =
"queueId[" + requestHeader.getQueueId() + "] is illagal,Topic :"
+ requestHeader.getTopic() + " topicConfig.readQueueNums: "
+ topicConfig.getReadQueueNums() + " consumer: " + channel.remoteAddress();
log.warn(errorInfo);
response.setCode(ResponseCode.SYSTEM_ERROR_VALUE);
response.setRemark(errorInfo);
return response;
}
// 订阅关系处理
SubscriptionData subscriptionData = null;
/**
* chen.si 需要处理消息tag过滤
*/
if (hasSubscriptionFlag) {
try {
/**
* chen.si consumer拉取消息，可以指定：
* 1. topic 只获取指定topic的消息
* 2. tag list 只获取具有指定tag的消息
*/
subscriptionData =
FilterAPI.buildSubscriptionData(requestHeader.getTopic(),
requestHeader.getSubscription());
}
catch (Exception e) {
log.warn("parse the consumer's subscription[{}] failed, group: {}",
requestHeader.getSubscription(),//
requestHeader.getConsumerGroup());
response.setCode(MQResponseCode.SUBSCRIPTION_PARSE_FAILED_VALUE);
response.setRemark("parse the consumer's subscription failed");
return response;
}
}
else {
ConsumerGroupInfo consumerGroupInfo =
this.brokerController.getConsumerManager().getConsumerGroupInfo(
requestHeader.getConsumerGroup());
if (null == consumerGroupInfo) {
log.warn("the consumer's group info not exist, group: {}", requestHeader.getConsumerGroup());
response.setCode(MQResponseCode.SUBSCRIPTION_NOT_EXIST_VALUE);
response.setRemark("the consumer's group info not exist"
+ FAQUrl.suggestTodo(FAQUrl.SAME_GROUP_DIFFERENT_TOPIC));
return response;
}
if (!subscriptionGroupConfig.isConsumeBroadcastEnable() //
&& consumerGroupInfo.getMessageModel() == MessageModel.BROADCASTING) {
response.setCode(MQResponseCode.NO_PERMISSION_VALUE);
response.setRemark("the consumer group[" + requestHeader.getConsumerGroup()
+ "] can not consume by broadcast way");
return response;
}
subscriptionData = consumerGroupInfo.findSubscriptionData(requestHeader.getTopic());
if (null == subscriptionData) {
log.warn("the consumer's subscription not exist, group: {}", requestHeader.getConsumerGroup());
response.setCode(MQResponseCode.SUBSCRIPTION_NOT_EXIST_VALUE);
response.setRemark("the consumer's subscription not exist"
+ FAQUrl.suggestTodo(FAQUrl.SAME_GROUP_DIFFERENT_TOPIC));
return response;
}
// 判断Broker的订阅关系版本是否最新
if (subscriptionData.getSubVersion() < requestHeader.getSubVersion()) {
log.warn("the broker's subscription is not latest, group: {} {}",
requestHeader.getConsumerGroup(), subscriptionData.getSubString());
response.setCode(MQResponseCode.SUBSCRIPTION_NOT_LATEST_VALUE);
response.setRemark("the consumer's subscription not latest");
return response;
}
}
final GetMessageResult getMessageResult =
this.brokerController.getMessageStore().getMessage(requestHeader.getTopic(),
requestHeader.getQueueId(), requestHeader.getQueueOffset(),
requestHeader.getMaxMsgNums(), subscriptionData);
if (getMessageResult != null) {
if (getMessageResult.getBufferTotalSize() > 0) {
PullmsgLiveMoniter.printProcessRequestLive(channel, request, getMessageResult);
}
response.setRemark(getMessageResult.getStatus().name());
responseHeader.setNextBeginOffset(getMessageResult.getNextBeginOffset());
responseHeader.setMinOffset(getMessageResult.getMinOffset());
responseHeader.setMaxOffset(getMessageResult.getMaxOffset());
// 消费较慢，重定向到另外一台机器
if (getMessageResult.isSuggestPullingFromSlave()) {
responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig
.getWhichBrokerWhenConsumeSlowly());
}
// 消费正常，按照订阅组配置重定向
else {
responseHeader.setSuggestWhichBrokerId(subscriptionGroupConfig.getBrokerId());
}
switch (getMessageResult.getStatus()) {
case FOUND:
response.setCode(ResponseCode.SUCCESS_VALUE);
break;
case MESSAGE_WAS_REMOVING:
response.setCode(MQResponseCode.PULL_RETRY_IMMEDIATELY_VALUE);
break;
// 这两个返回值都表示服务器暂时没有这个队列，应该立刻将客户端Offset重置为0
case NO_MATCHED_LOGIC_QUEUE:
case NO_MESSAGE_IN_QUEUE:
if (0 != requestHeader.getQueueOffset()) {
response.setCode(MQResponseCode.PULL_OFFSET_MOVED_VALUE);
log.info(
"the broker store no queue data, fix the request offset {} to {}, Topic: {} QueueId: {} Consumer Group: {}",//
requestHeader.getQueueOffset(), //
getMessageResult.getNextBeginOffset(), //
requestHeader.getTopic(),//
requestHeader.getQueueId(),//
requestHeader.getConsumerGroup()//
);
}
else {
response.setCode(MQResponseCode.PULL_NOT_FOUND_VALUE);
}
break;
case NO_MATCHED_MESSAGE:
response.setCode(MQResponseCode.PULL_RETRY_IMMEDIATELY_VALUE);
break;
case OFFSET_FOUND_NULL:
response.setCode(MQResponseCode.PULL_NOT_FOUND_VALUE);
break;
case OFFSET_OVERFLOW_BADLY:
response.setCode(MQResponseCode.PULL_OFFSET_MOVED_VALUE);
log.info("the request offset: " + requestHeader.getQueueOffset()
+ " over flow badly, broker max offset: " + getMessageResult.getMaxOffset()
+ ", consumer: " + channel.remoteAddress());
break;
case OFFSET_OVERFLOW_ONE:
response.setCode(MQResponseCode.PULL_NOT_FOUND_VALUE);
break;
case OFFSET_TOO_SMALL:
response.setCode(MQResponseCode.PULL_OFFSET_MOVED_VALUE);
log.info("the request offset: " + requestHeader.getQueueOffset()
+ " too small, broker min offset: " + getMessageResult.getMinOffset()
+ ", consumer: " + channel.remoteAddress());
break;
default:
assert false;
break;
}
switch (response.getCode()) {
case ResponseCode.SUCCESS_VALUE:
try {
FileRegion fileRegion =
new ManyMessageTransfer(response.encodeHeader(getMessageResult
.getBufferTotalSize()), getMessageResult);
channel.writeAndFlush(fileRegion).addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
getMessageResult.release();
if (!future.isSuccess()) {
log.error(
"transfer many message by pagecache failed, " + channel.remoteAddress(),
future.cause());
}
}
});
}
catch (Throwable e) {
log.error("", e);
getMessageResult.release();
}
response = null;
break;
case MQResponseCode.PULL_NOT_FOUND_VALUE:
// 长轮询
if (brokerAllowSuspend && hasSuspendFlag) {
/*
* chen.si 此处认为是长轮询，可以block一段时间
*/
PullRequest pullRequest =
new PullRequest(request, channel, suspendTimeoutMillisLong, this.brokerController
.getMessageStore().now(), requestHeader.getQueueOffset());
this.brokerController.getPullRequestHoldService().suspendPullRequest(
requestHeader.getTopic(), requestHeader.getQueueId(), pullRequest);
response = null;
break;
}
// 向Consumer返回应答
case MQResponseCode.PULL_RETRY_IMMEDIATELY_VALUE:
case MQResponseCode.PULL_OFFSET_MOVED_VALUE:
break;
default:
assert false;
}
}
else {
response.setCode(ResponseCode.SYSTEM_ERROR_VALUE);
response.setRemark("store getMessage return null");
}
// 存储Consumer消费进度
boolean storeOffsetEnable = brokerAllowSuspend; // 说明是首次调用，相对于长轮询通知
/*
* chen.si 可以自动提交offset
*/
storeOffsetEnable = storeOffsetEnable && hasCommitOffsetFlag; // 说明Consumer设置了标志位
storeOffsetEnable = storeOffsetEnable // 只有Master支持存储offset
&& this.brokerController.getMessageStoreConfig().getBrokerRole() != BrokerRole.SLAVE;
if (storeOffsetEnable) {
this.brokerController.getConsumerOffsetManager().commitOffset(requestHeader.getConsumerGroup(),
requestHeader.getTopic(), requestHeader.getQueueId(), requestHeader.getCommitOffset());
}
return response;
}
}