rocketmq源码系列-producer（三）

在rocketmq发送端，

发送一个顺序消息的代码如图，看看都干了什么

public class OrderProducer {
    public static void main(String[] args) throws InterruptedException, RemotingException, MQClientException, MQBrokerException {
        DefaultMQProducer producer = new DefaultMQProducer("rocket_test_topic");
        producer.setNamesrvAddr("192.168.1.229:9876;192.168.1.226:9876");
        producer.start();
        String[] tags = new String[] {"TagA", "TagB", "TagC", "TagD", "TagE"};
        for (int i = 0; i < 10000; i++) {
            Message message = new Message("rocket_test_topic",tags[0],"i"+i,("rocket_test"+i).getBytes());
            SendResult send = producer.send(message, new MessageQueueSelector() {
                @Override
                public MessageQueue select(List<MessageQueue> list, Message message, Object o) {
                    Integer id = (Integer) o;
                    MessageQueue messageQueue = list.get(id);
                    return list.get(id);
                }
            }, i%4);//队列0

            String msgId = send.getMsgId();
            System.out.println(msgId+send);
            TimeUnit.MILLISECONDS.sleep(3);
        }
     }
   }

先看下producer端的启动流程

org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl#start(boolean)

 public void start(final boolean startFactory) throws MQClientException {
        switch (this.serviceState) {
            case CREATE_JUST:
                this.serviceState = ServiceState.START_FAILED;

                this.checkConfig();//producerGroup验证,producerGroup不能为空，正则，长度验证等

                if (!this.defaultMQProducer.getProducerGroup().equals(MixAll.CLIENT_INNER_PRODUCER_GROUP)) {
                    // RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean();String name = runtime.getName()获取pid和本机名称
                    this.defaultMQProducer.changeInstanceNameToPID();//将实例名称由default改成pid，
                }

//                创建MQClientInstance实例,一个jvm实例就MQClientInstance实例
                this.mQClientFactory = MQClientManager.getInstance().getAndCreateMQClientInstance(this.defaultMQProducer, rpcHook);

                //DefaultMQProducerImpl实例注册到producerTable
                boolean registerOK = mQClientFactory.registerProducer(this.defaultMQProducer.getProducerGroup(), this);
                if (!registerOK) {
                    this.serviceState = ServiceState.CREATE_JUST;
                    throw new MQClientException("The producer group[" + this.defaultMQProducer.getProducerGroup()
                        + "] has been created before, specify another name please." + FAQUrl.suggestTodo(FAQUrl.GROUP_NAME_DUPLICATE_URL),
                        null);
                }

                //topicPublishInfoTable路由信息放入TBW102,创建的
                this.topicPublishInfoTable.put(this.defaultMQProducer.getCreateTopicKey(), new TopicPublishInfo());

                if (startFactory) {//传进来就是true
                    mQClientFactory.start();//对mqclieninstance就行一次start方法，  #1
                }

                log.info("the producer [{}] start OK. sendMessageWithVIPChannel={}", this.defaultMQProducer.getProducerGroup(),
                    this.defaultMQProducer.isSendMessageWithVIPChannel());
                this.serviceState = ServiceState.RUNNING;
                break;
            case RUNNING:
            case START_FAILED:
            case SHUTDOWN_ALREADY:
                throw new MQClientException("The producer service state not OK, maybe started once, "
                    + this.serviceState
                    + FAQUrl.suggestTodo(FAQUrl.CLIENT_SERVICE_NOT_OK),
                    null);
            default:
                break;
        }
        //发送心跳数据到所有的broker
        this.mQClientFactory.sendHeartbeatToAllBrokerWithLock();
    }


#1
 public void start() throws MQClientException {//mqclientinstacne的初始化
        synchronized (this) {
            switch (this.serviceState) {
                case CREATE_JUST:
                    this.serviceState = ServiceState.START_FAILED;
                    // If not specified,looking address from name server
                    if (null == this.clientConfig.getNamesrvAddr()) {
                        this.mQClientAPIImpl.fetchNameServerAddr();
                    }
                    // Start request-response channel，开启远程连接通道。
                    this.mQClientAPIImpl.start();
                    // Start various schedule tasks
                    this.startScheduledTask();//2分钟后取一次namerserver地址，30秒拉取一次topicinfo,30秒发送心跳给broker，持久化消费位移
                    // Start pull service  初始化拉取消息服务线程
                    this.pullMessageService.start();//pullmes
                    // Start rebalance service  负载均衡线程
                    this.rebalanceService.start();
                    // Start push service//创建producer实例
                    this.defaultMQProducer.getDefaultMQProducerImpl().start(false);
                    log.info("the client factory [{}] start OK", this.clientId);
                    this.serviceState = ServiceState.RUNNING;
                    break;
                case RUNNING:
                    break;
                case SHUTDOWN_ALREADY:
                    break;
                case START_FAILED:
                    throw new MQClientException("The Factory object[" + this.getClientId() + "] has been created before, and failed.", null);
                default:
                    break;
            }
        }
    }

 

然后就是真正的send方法了。

 /**
     *
     * @param msg  发送的消息
     * @param selector 选择的队列
     * @param arg 透传数据
     * @param communicationMode
     * @param sendCallback 回调函数
     * @param timeout 默认超时时间3秒
     * @return

     */
    private SendResult sendSelectImpl(
        Message msg,
        MessageQueueSelector selector,
        Object arg,
        final CommunicationMode communicationMode,
        final SendCallback sendCallback, final long timeout
    ) throws MQClientException, RemotingException, MQBrokerException, InterruptedException {
        long beginStartTime = System.currentTimeMillis();
        this.makeSureStateOK();
        Validators.checkMessage(msg, this.defaultMQProducer);

        //从缓存获取路由信息，获取不到就从远程获取 #2
        TopicPublishInfo topicPublishInfo = this.tryToFindTopicPublishInfo(msg.getTopic());
        if (topicPublishInfo != null && topicPublishInfo.ok()) {
            MessageQueue mq = null;
            try {//选取的队列
                mq = selector.select(topicPublishInfo.getMessageQueueList(), msg, arg);
            } catch (Throwable e) {
                throw new MQClientException("select message queue throwed exception.", e);
            }

            long costTime = System.currentTimeMillis() - beginStartTime;
            if (timeout < costTime) {
                throw new RemotingTooMuchRequestException("sendSelectImpl call timeout");
            }
            if (mq != null) {//发送流程
                return this.sendKernelImpl(msg, mq, communicationMode, sendCallback, null, timeout - costTime);
            } else {
                throw new MQClientException("select message queue return null.", null);
            }
        }

        throw new MQClientException("No route info for this topic, " + msg.getTopic(), null);
    }

#2

org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl#tryToFindTopicPublishInfo

org.apache.rocketmq.client.impl.factory.MQClientInstance#updateTopicRouteInfoFromNameServer(java.lang.String, boolean, org.apache.rocketmq.client.producer.DefaultMQProducer)

    public boolean updateTopicRouteInfoFromNameServer(final String topic, boolean isDefault,
        DefaultMQProducer defaultMQProducer) {
        try {//lockNamesrv并发锁下
            if (this.lockNamesrv.tryLock(LOCK_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)) {
                try {
                    TopicRouteData topicRouteData;
                    if (isDefault && defaultMQProducer != null) {
                        topicRouteData = this.mQClientAPIImpl.getDefaultTopicRouteInfoFromNameServer(defaultMQProducer.getCreateTopicKey(),
                            1000 * 3);
                        if (topicRouteData != null) {
                            for (QueueData data : topicRouteData.getQueueDatas()) {
                                int queueNums = Math.min(defaultMQProducer.getDefaultTopicQueueNums(), data.getReadQueueNums());
                                data.setReadQueueNums(queueNums);
                                data.setWriteQueueNums(queueNums);
                            }
                        }
                    } else {//从nameserver获取路由信息 第一次isDefault为false，从namesrv获取理由信息
                        topicRouteData = this.mQClientAPIImpl.getTopicRouteInfoFromNameServer(topic, 1000 * 3);
                    }
                    if (topicRouteData != null) {//说明拿到了路由数据
                        TopicRouteData old = this.topicRouteTable.get(topic);
                        boolean changed = topicRouteDataIsChange(old, topicRouteData);//根据之前的和现在 判断路由信息是否变化
                        if (!changed) {
                            changed = this.isNeedUpdateTopicRouteInfo(topic);//判断是否需要需要更新producer,和consumer的路由信息
                        } else {
                            log.info("the topic[{}] route info changed, old[{}] ,new[{}]", topic, old, topicRouteData);
                        }

                        if (changed) {
                            TopicRouteData cloneTopicRouteData = topicRouteData.cloneTopicRouteData();//拷贝一份数据出来

                            for (BrokerData bd : topicRouteData.getBrokerDatas()) {
                                this.brokerAddrTable.put(bd.getBrokerName(), bd.getBrokerAddrs());//更新brokeraddrtable
                            }

                            // Update Pub info
                            {//实体封装
                                TopicPublishInfo publishInfo = topicRouteData2TopicPublishInfo(topic, topicRouteData);
                                publishInfo.setHaveTopicRouterInfo(true);
                                Iterator<Entry<String, MQProducerInner>> it = this.producerTable.entrySet().iterator();//会有多个producer
                                while (it.hasNext()) {
                                    Entry<String, MQProducerInner> entry = it.next();
                                    MQProducerInner impl = entry.getValue();
                                    if (impl != null) {
                                        impl.updateTopicPublishInfo(topic, publishInfo);//更新topicPublishInfoTable，直接覆盖历史数据
                                    }
                                }
                            }

                            // Update sub info
                            {
                                Set<MessageQueue> subscribeInfo = topicRouteData2TopicSubscribeInfo(topic, topicRouteData);
                                Iterator<Entry<String, MQConsumerInner>> it = this.consumerTable.entrySet().iterator();
                                while (it.hasNext()) {
                                    Entry<String, MQConsumerInner> entry = it.next();
                                    MQConsumerInner impl = entry.getValue();
                                    if (impl != null) {
                                        impl.updateTopicSubscribeInfo(topic, subscribeInfo);
                                    }
                                }
                            }
                            log.info("topicRouteTable.put. Topic = {}, TopicRouteData[{}]", topic, cloneTopicRouteData);
                            this.topicRouteTable.put(topic, cloneTopicRouteData);
                            return true;
                        }
                    } else {
                        log.warn("updateTopicRouteInfoFromNameServer, getTopicRouteInfoFromNameServer return null, Topic: {}", topic);
                    }
                } catch (Exception e) {
                    if (!topic.startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX) && !topic.equals(MixAll.AUTO_CREATE_TOPIC_KEY_TOPIC)) {
                        log.warn("updateTopicRouteInfoFromNameServer Exception", e);
                    }
                } finally {
                    this.lockNamesrv.unlock();
                }
            } else {
                log.warn("updateTopicRouteInfoFromNameServer tryLock timeout {}ms", LOCK_TIMEOUT_MILLIS);
            }
        } catch (InterruptedException e) {
            log.warn("updateTopicRouteInfoFromNameServer Exception", e);
        }

        return false;
    }

消息发送

 private SendResult sendKernelImpl(final Message msg,
                                      final MessageQueue mq,
                                      final CommunicationMode communicationMode,
                                      final SendCallback sendCallback,
                                      final TopicPublishInfo topicPublishInfo,
                                      final long timeout) throws MQClientException, RemotingException, MQBrokerException, InterruptedException {
        long beginStartTime = System.currentTimeMillis();
        String brokerAddr = this.mQClientFactory.findBrokerAddressInPublish(mq.getBrokerName());//只获取master节点
        if (null == brokerAddr) {
            tryToFindTopicPublishInfo(mq.getTopic());//如果没找到 更新下路由信息
            brokerAddr = this.mQClientFactory.findBrokerAddressInPublish(mq.getBrokerName());
        }

        SendMessageContext context = null;
        if (brokerAddr != null) {
            brokerAddr = MixAll.brokerVIPChannel(this.defaultMQProducer.isSendMessageWithVIPChannel(), brokerAddr);

            byte[] prevBody = msg.getBody();
            try {
                //for MessageBatch,ID has been set in the generating process
                if (!(msg instanceof MessageBatch)) {
                    MessageClientIDSetter.setUniqID(msg);
                }

                int sysFlag = 0;
                boolean msgBodyCompressed = false;
                if (this.tryToCompressMessage(msg)) {//是否进行消息压缩
                    sysFlag |= MessageSysFlag.COMPRESSED_FLAG;
                    msgBodyCompressed = true;
                }

                final String tranMsg = msg.getProperty(MessageConst.PROPERTY_TRANSACTION_PREPARED);//有这个属性 事务消息
                if (tranMsg != null && Boolean.parseBoolean(tranMsg)) {
                    sysFlag |= MessageSysFlag.TRANSACTION_PREPARED_TYPE;
                }

                if (hasCheckForbiddenHook()) {
                    CheckForbiddenContext checkForbiddenContext = new CheckForbiddenContext();
                    checkForbiddenContext.setNameSrvAddr(this.defaultMQProducer.getNamesrvAddr());
                    checkForbiddenContext.setGroup(this.defaultMQProducer.getProducerGroup());
                    checkForbiddenContext.setCommunicationMode(communicationMode);
                    checkForbiddenContext.setBrokerAddr(brokerAddr);
                    checkForbiddenContext.setMessage(msg);
                    checkForbiddenContext.setMq(mq);
                    checkForbiddenContext.setUnitMode(this.isUnitMode());
                    this.executeCheckForbiddenHook(checkForbiddenContext);
                }

                if (this.hasSendMessageHook()) {//发送之前，钩子函数，
                    context = new SendMessageContext();
                    context.setProducer(this);
                    context.setProducerGroup(this.defaultMQProducer.getProducerGroup());
                    context.setCommunicationMode(communicationMode);
                    context.setBornHost(this.defaultMQProducer.getClientIP());
                    context.setBrokerAddr(brokerAddr);
                    context.setMessage(msg);
                    context.setMq(mq);
                    String isTrans = msg.getProperty(MessageConst.PROPERTY_TRANSACTION_PREPARED);
                    if (isTrans != null && isTrans.equals("true")) {
                        context.setMsgType(MessageType.Trans_Msg_Half);
                    }

                    if (msg.getProperty("__STARTDELIVERTIME") != null || msg.getProperty(MessageConst.PROPERTY_DELAY_TIME_LEVEL) != null) {
                        context.setMsgType(MessageType.Delay_Msg);
                    }
                    this.executeSendMessageHookBefore(context);
                }

                SendMessageRequestHeader requestHeader = new SendMessageRequestHeader();
                requestHeader.setProducerGroup(this.defaultMQProducer.getProducerGroup());
                requestHeader.setTopic(msg.getTopic());
                requestHeader.setDefaultTopic(this.defaultMQProducer.getCreateTopicKey());
                requestHeader.setDefaultTopicQueueNums(this.defaultMQProducer.getDefaultTopicQueueNums());
                requestHeader.setQueueId(mq.getQueueId());
                requestHeader.setSysFlag(sysFlag);
                requestHeader.setBornTimestamp(System.currentTimeMillis());
                requestHeader.setFlag(msg.getFlag());
                requestHeader.setProperties(MessageDecoder.messageProperties2String(msg.getProperties()));
                requestHeader.setReconsumeTimes(0);
                requestHeader.setUnitMode(this.isUnitMode());
                requestHeader.setBatch(msg instanceof MessageBatch);
                if (requestHeader.getTopic().startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX)) {//说明是重试消息
                    String reconsumeTimes = MessageAccessor.getReconsumeTime(msg);
                    if (reconsumeTimes != null) {
                        requestHeader.setReconsumeTimes(Integer.valueOf(reconsumeTimes));
                        MessageAccessor.clearProperty(msg, MessageConst.PROPERTY_RECONSUME_TIME);//重试次数
                    }

                    String maxReconsumeTimes = MessageAccessor.getMaxReconsumeTimes(msg);
                    if (maxReconsumeTimes != null) {
                        requestHeader.setMaxReconsumeTimes(Integer.valueOf(maxReconsumeTimes));//最大重试次数
                        MessageAccessor.clearProperty(msg, MessageConst.PROPERTY_MAX_RECONSUME_TIMES);
                    }
                }

                SendResult sendResult = null;
                switch (communicationMode) {
                    case ASYNC:
                        Message tmpMessage = msg;
                        if (msgBodyCompressed) {
                            //If msg body was compressed, msgbody should be reset using prevBody.
                            //Clone new message using commpressed message body and recover origin massage.
                            //Fix bug:https://github.com/apache/rocketmq-externals/issues/66
                            tmpMessage = MessageAccessor.cloneMessage(msg);
                            msg.setBody(prevBody);
                        }
                        long costTimeAsync = System.currentTimeMillis() - beginStartTime;
                        if (timeout < costTimeAsync) {
                            throw new RemotingTooMuchRequestException("sendKernelImpl call timeout");
                        }
                        sendResult = this.mQClientFactory.getMQClientAPIImpl().sendMessage(
                            brokerAddr,
                            mq.getBrokerName(),
                            tmpMessage,
                            requestHeader,
                            timeout - costTimeAsync,
                            communicationMode,
                            sendCallback,
                            topicPublishInfo,
                            this.mQClientFactory,
                            this.defaultMQProducer.getRetryTimesWhenSendAsyncFailed(),
                            context,
                            this);
                        break;
                    case ONEWAY:
                    case SYNC:
                        long costTimeSync = System.currentTimeMillis() - beginStartTime;
                        if (timeout < costTimeSync) {
                            throw new RemotingTooMuchRequestException("sendKernelImpl call timeout");
                        }
                        sendResult = this.mQClientFactory.getMQClientAPIImpl().sendMessage(
                            brokerAddr,
                            mq.getBrokerName(),
                            msg,
                            requestHeader,
                            timeout - costTimeSync,
                            communicationMode,
                            context,
                            this);
                        break;
                    default:
                        assert false;
                        break;
                }

                if (this.hasSendMessageHook()) {
                    context.setSendResult(sendResult);
                    this.executeSendMessageHookAfter(context);
                }

                return sendResult;
            } catch (RemotingException e) {
                if (this.hasSendMessageHook()) {
                    context.setException(e);
                    this.executeSendMessageHookAfter(context);
                }
                throw e;
            } catch (MQBrokerException e) {
                if (this.hasSendMessageHook()) {
                    context.setException(e);
                    this.executeSendMessageHookAfter(context);
                }
                throw e;
            } catch (InterruptedException e) {
                if (this.hasSendMessageHook()) {
                    context.setException(e);
                    this.executeSendMessageHookAfter(context);
                }
                throw e;
            } finally {
                msg.setBody(prevBody);
            }
        }

        throw new MQClientException("The broker[" + mq.getBrokerName() + "] not exist", null);
    }