23.RocketMQ之NameServer处理Broker心跳包,更新本地路由信息

NameServer处理Broker心跳包,更新本地路由信息

DefaultRequestProcessor继承自NettyRequestProcessor:处理各种客户端的请求，如果请求类型是为REGISTER_BROKER，则将请求转发到RouteInfoManager#regiesterBroker,主要是服务器端或者客户端或者broker发送心跳,看下如何处理请求类型是为REGISTER_BROKER的请求吧

DefaultRequestProcessor#processRequest

java @Override public RemotingCommand processRequest(ChannelHandlerContext ctx, RemotingCommand request) throws RemotingCommandException { if (ctx != null) { log.debug("receive request, {} {} {}", request.getCode(), RemotingHelper.parseChannelRemoteAddr(ctx.channel()), request); } switch (request.getCode()) { case RequestCode.PUT_KV_CONFIG: return this.putKVConfig(ctx, request); case RequestCode.GET_KV_CONFIG: return this.getKVConfig(ctx, request); case RequestCode.DELETE_KV_CONFIG: return this.deleteKVConfig(ctx, request); case RequestCode.QUERY_DATA_VERSION: return queryBrokerTopicConfig(ctx, request); //注册broker case RequestCode.REGISTER_BROKER: Version brokerVersion = MQVersion.value2Version(request.getVersion()); if (brokerVersion.ordinal() >= MQVersion.Version.V3_0_11.ordinal()) { return this.registerBrokerWithFilterServer(ctx, request); } else { return this.registerBroker(ctx, request); } //取消注册broker case RequestCode.UNREGISTER_BROKER: return this.unregisterBroker(ctx, request); //拉取路由元信息 case RequestCode.GET_ROUTEINTO_BY_TOPIC: return this.getRouteInfoByTopic(ctx, request); case RequestCode.GET_BROKER_CLUSTER_INFO: return this.getBrokerClusterInfo(ctx, request); case RequestCode.WIPE_WRITE_PERM_OF_BROKER: return this.wipeWritePermOfBroker(ctx, request); case RequestCode.GET_ALL_TOPIC_LIST_FROM_NAMESERVER: return getAllTopicListFromNameserver(ctx, request); case RequestCode.DELETE_TOPIC_IN_NAMESRV: return deleteTopicInNamesrv(ctx, request); case RequestCode.GET_KVLIST_BY_NAMESPACE: return this.getKVListByNamespace(ctx, request); case RequestCode.GET_TOPICS_BY_CLUSTER: return this.getTopicsByCluster(ctx, request); case RequestCode.GET_SYSTEM_TOPIC_LIST_FROM_NS: return this.getSystemTopicListFromNs(ctx, request); case RequestCode.GET_UNIT_TOPIC_LIST: return this.getUnitTopicList(ctx, request); case RequestCode.GET_HAS_UNIT_SUB_TOPIC_LIST: return this.getHasUnitSubTopicList(ctx, request); case RequestCode.GET_HAS_UNIT_SUB_UNUNIT_TOPIC_LIST: return this.getHasUnitSubUnUnitTopicList(ctx, request); //更新nameConfig case RequestCode.UPDATE_NAMESRV_CONFIG: return this.updateConfig(ctx, request); //拉取nameConfig case RequestCode.GET_NAMESRV_CONFIG: return this.getConfig(ctx, request); default: break; } return null; }

注册broker,维护topic和队列信息

DefaultRequestProcessor#registerBroker

```java public RemotingCommand registerBroker(ChannelHandlerContext ctx, RemotingCommand request) throws RemotingCommandException { final RemotingCommand response = RemotingCommand.createResponseCommand (RegisterBrokerResponseHeader.class);

final RegisterBrokerResponseHeader responseHeader
            = (RegisterBrokerResponseHeader)response.readCustomHeader();

final RegisterBrokerRequestHeader requestHeader
            = (RegisterBrokerRequestHeader)request
                        .decodeCommandCustomHeader          
                            (RegisterBrokerRequestHeader.class);

if (!checksum(ctx, request, requestHeader)) { response.setCode(ResponseCode.SYSTEM_ERROR); response.setRemark("crc32 not match"); return response; } TopicConfigSerializeWrapper topicConfigWrapper; if (request.getBody() != null) { topicConfigWrapper = TopicConfigSerializeWrapper .decode(request.getBody(), TopicConfigSerializeWrapper.class); } else { topicConfigWrapper = new TopicConfigSerializeWrapper(); topicConfigWrapper.getDataVersion().setCounter(new AtomicLong(0)); topicConfigWrapper.getDataVersion().setTimestamp(0); }

//注册broker 维护路由信息
RegisterBrokerResult result = this.namesrvController
                                .getRouteInfoManager()
                                .registerBroker(
                                    requestHeader.getClusterName(),
                                    requestHeader.getBrokerAddr(),
                                    requestHeader.getBrokerName(),
                                    requestHeader.getBrokerId(),
                                    requestHeader.getHaServerAddr(),
                                    topicConfigWrapper,
                                    null,
                                    ctx.channel());

responseHeader.setHaServerAddr(result.getHaServerAddr());
responseHeader.setMasterAddr(result.getMasterAddr());
byte[] jsonValue = this.namesrvController
                        .getKvConfigManager()
                        .getKVListByNamespace
                        (NamesrvUtil.NAMESPACE_ORDER_TOPIC_CONFIG);
response.setBody(jsonValue);
response.setCode(ResponseCode.SUCCESS);
response.setRemark(null);
return response;

} ```

RouteInfoManager#registerBroker

```java public RegisterBrokerResult registerBroker( final String clusterName, final String brokerAddr, final String brokerName, final long brokerId, final String haServerAddr, final TopicConfigSerializeWrapper topicConfigWrapper, final List filterServerList, final Channel channel) { RegisterBrokerResult result = new RegisterBrokerResult(); try { try { //加锁 this.lock.writeLock().lockInterruptibly(); //维护clusterAddrTable Set brokerNames = this.clusterAddrTable.get(clusterName); if (null == brokerNames) { brokerNames = new HashSet (); this.clusterAddrTable.put(clusterName, brokerNames); } //将当前broker添加到集合中 brokerNames.add(brokerName);

boolean registerFirst = false;
        //维护brokerAddrTable
        BrokerData brokerData = this.brokerAddrTable.get(brokerName);
        if (null == brokerData) {
            registerFirst = true;
            brokerData = new BrokerData
                    (clusterName, brokerName, new HashMap<Long, String>());
            this.brokerAddrTable.put(brokerName, brokerData);
        }
        //非第一次注册,更新Broker
        Map<Long, String> brokerAddrsMap = brokerData.getBrokerAddrs();

        Iterator<Entry<Long, String>> it = brokerAddrsMap.entrySet().iterator();
        while (it.hasNext()) {
            Entry<Long, String> item = it.next();
            if (null != brokerAddr && brokerAddr.equals(item.getValue()) && brokerId != item.getKey()) {
                it.remove();
            }
        }

String oldAddr = brokerData.getBrokerAddrs().put(brokerId, brokerAddr); registerFirst = registerFirst || (null == oldAddr); //维护topicQueueTable if (null != topicConfigWrapper && MixAll.MASTER_ID == brokerId) { if (this.isBrokerTopicConfigChanged (brokerAddr, topicConfigWrapper.getDataVersion()) || registerFirst) {

ConcurrentMap<String, TopicConfig> tcTable = 
                            topicConfigWrapper.getTopicConfigTable();

                if (tcTable != null) {
                    for (Map.Entry<String, TopicConfig> entry : tcTable.entrySet()) {
                        //HashMap<String/* topic */, List<QueueData>> topicQueueTable;
                        this.createAndUpdateQueueData(brokerName, entry.getValue());
                    }
                }
            }
        }
        //维护brokerLiveTable
        BrokerLiveInfo prevBrokerLiveInfo = this.brokerLiveTable.put(brokerAddr,
            new BrokerLiveInfo(
                System.currentTimeMillis(),
                topicConfigWrapper.getDataVersion(),
                channel,
                haServerAddr));
        if (null == prevBrokerLiveInfo) {
            log.info("new broker registered, {} HAServer: {}", brokerAddr, haServerAddr);
        }
        //维护filterServerList
        if (filterServerList != null) {
            if (filterServerList.isEmpty()) {
                this.filterServerTable.remove(brokerAddr);
            } else {
                this.filterServerTable.put(brokerAddr, filterServerList);
            }
        }

if (MixAll.MASTERID != brokerId) { String masterAddr = brokerData.getBrokerAddrs().get(MixAll.MASTERID); if (masterAddr != null) { BrokerLiveInfo brokerLiveInfo = this.brokerLiveTable.get(masterAddr); if (brokerLiveInfo != null) { result.setHaServerAddr(brokerLiveInfo.getHaServerAddr()); result.setMasterAddr(masterAddr); } } } } finally { this.lock.writeLock().unlock(); } } catch (Exception e) { log.error("registerBroker Exception", e); } return result; } ```

RouteInfoManager#createAndUpdateQueueData

```java private void createAndUpdateQueueData(final String brokerName, final TopicConfig topicConfig) { // HashMap > topicQueueTable; //创建QueueData QueueData就是topicQueueTable对应的List中的元素 QueueData queueData = new QueueData(); queueData.setBrokerName(brokerName); queueData.setWriteQueueNums(topicConfig.getWriteQueueNums()); queueData.setReadQueueNums(topicConfig.getReadQueueNums()); queueData.setPerm(topicConfig.getPerm()); queueData.setTopicSynFlag(topicConfig.getTopicSysFlag()); //获得topicQueueTable中队列集合 List queueDataList = this.topicQueueTable.get(topicConfig.getTopicName()); //topicQueueTable为空,则直接创建一个list并将queueData添加到队列集合 if (null == queueDataList) { queueDataList = new LinkedList (); queueDataList.add(queueData); this.topicQueueTable.put(topicConfig.getTopicName(), queueDataList); log.info("new topic registered, {} {}", topicConfig.getTopicName(), queueData); } else { //判断是否是新的队列 boolean addNewOne = true; Iterator it = queueDataList.iterator(); while (it.hasNext()) { QueueData qd = it.next();

//假如原来topicA对应的是braoker-a broker-b
            //现在新增broker-c
            //那么qd.getBrokerName().equals(brokerName) 肯定是不相等的
            //这样才能加入queueDataList

            //如果brokerName相同,代表不是新的队列
            if (qd.getBrokerName().equals(brokerName)) {
                    if (qd.equals(queueData)) {
                        addNewOne = false;
                    } else {
                        it.remove();
                    }
                }
        }
    //如果是新的队列,则添加队列到queueDataList
    if (addNewOne) {
        queueDataList.add(queueData);
    }
}

} ```

生产者&消费者如何定时拉取路由元信息？

是在哪里请求的,多久请求一次？

RocketMQ路由发现是非实时的，当Topic路由出现变化后，NameServer不会主动推送给客户端，而是由客户端定时拉取主题最新的路由.客户端指的是消费者和生产者。

发起getRouteInfoByTopic请求的是MQClientInstance。生产者和消费者都会启动MQClientInstance。

MQClientInstance会启动1个定时任务每30秒拉一次最新的路由信息。

此时会由DefaultRequestProcessor处理这些请求。请求的key是GET_ROUTEINFO_BY_TOPIC.

具体代码如下:

java case RequestCode.GET_ROUTEINFO_BY_TOPIC: return this.getRouteInfoByTopic(ctx, request);

DefaultRequestProcessor#getRouteInfoByTopic

java public RemotingCommand getRouteInfoByTopic(ChannelHandlerContext ctx, RemotingCommand request) throws RemotingCommandException { final RemotingCommand response = RemotingCommand.createResponseCommand(null); final GetRouteInfoRequestHeader requestHeader = (GetRouteInfoRequestHeader) request.decodeCommandCustomHeader(GetRouteInfoRequestHeader.class); // 调用RouteInfoManager的方法 // 从路由表topicQueueTable、brokerAddrTable、filterServerTable中 // 分别填充TopicRouteData的List<QueueData>、List<BrokerData>、filterServer TopicRouteData topicRouteData = this.namesrvController .getRouteInfoManager() .pickupTopicRouteData(requestHeader.getTopic()); //如果找到主题对应你的路由信息并且该主题为顺序消息 //则从NameServer KVConfig中获取关于顺序消息相关的配置填充路由信息 if (topicRouteData != null) { if (this.namesrvController.getNamesrvConfig().isOrderMessageEnable()) { String orderTopicConf = this.namesrvController .getKvConfigManager().getKVConfig (NamesrvUtil.NAMESPACE_ORDER_TOPIC_CONFIG, requestHeader.getTopic()); topicRouteData.setOrderTopicConf(orderTopicConf); } byte[] content = topicRouteData.encode(); response.setBody(content); response.setCode(ResponseCode.SUCCESS); response.setRemark(null); return response; } response.setCode(ResponseCode.TOPIC_NOT_EXIST); response.setRemark ("No topic route info in name server for the topic: " + requestHeader.getTopic()+ FAQUrl.suggestTodo(FAQUrl.APPLY_TOPIC_URL)); return response; }