RocketMQ之NameServer學習筆記

阿新 • • 發佈：2019-04-28

生產者 com next() 相關配置 pty @override || eth lse

org.apache.rocketmq.namesrv.NamesrvController

NameserController,NameServer的核心控制類。

1.1 NamesrvConfig

NamesrvConfig,主要指定nameserver的相關配置目錄屬性

1）kvConfigPath(kvConfig.json)

2）mqhome/namesrv/namesrv.properties

3）orderMessageEnable，是否開啟順序消息功能，默認為false

1.2 ScheduledExecutorService scheduledExecutorService

private final ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactoryIm pl("NSScheduledThread"));

NameServer 定時任務執行線程池，一個線程，默認定時執行兩個任務：

任務1、每隔10s掃描broker,維護當前存活的Broker信息

任務2、每隔10s打印KVConfig信息。

1.3 KVConfigManager

讀取或變更NameServer的配置屬性，加載NamesrvConfig中配置的配置文件到內存，此類一個亮點就是使用輕量級的非線程安全容器，再結合讀寫鎖對資源讀寫進行保護。盡最大程度提高線程的並發度。

1.4 RouteInfoManager

NameServer數據的載體，記錄Broker,Topic等信息。

//NameServer 與 Broker 空閑時長，默認2分鐘，在2分鐘內Nameserver沒有收到Broker的心跳包，則關閉該連接。 
private final static long BROKER_CHANNEL_EXPIRED_TIME = 1000 * 60 * 2;  
 
//讀寫鎖，用來保護非線程安全容器HashMap                                       
    private final ReadWriteLock lock = new ReentrantReadWriteLock(); 
//topicQueueTable，主題與隊列關系，記錄一個主題的隊列分布在哪些Broker上，每個Broker上存在該主題的隊列個數                                                     
    private final HashMap<String/* topic */, List<QueueData>> topicQueueTable;  
    //brokerAddrTable,所有Broker信息，使用brokerName當key,BrokerData信息描述每一個broker信息。
    private final HashMap<String/* brokerName */, BrokerData> brokerAddrTable;
//clusterAddrTable，broker集群信息，每個集群包含哪些Broker                               
    private final HashMap<String/* clusterName */, Set<String/* brokerName */>> clusterAddrTable;   
//brokerLiveTable，當前存活的Broker,該信息不是實時的，NameServer每10S掃描一次所有的broker,根據心跳包的時間得知broker的狀態，該機制也是導致當一個master Down掉後，消息生產者無法感知，可能繼續向Down掉的Master發送消息，導致失敗
    private final HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;                                
    private final HashMap<String/* brokerAddr */, List<String>/* Filter Server */> filterServerTable;

/**
 *  Broker信息；key為brokerName，value為BrokerData
 */
private final HashMap<String/* brokerName */, BrokerData> brokerAddrTable;

public class BrokerData implements Comparable<BrokerData> {
    /**
     * Cluster名稱
     */
    private String cluster;
    /**
     * broker名稱
     */
    private String brokerName;
    /**
     * 0->ip:port
     */
    private HashMap<Long/* brokerId */, String/* broker address */> brokerAddrs;
}

註冊topic信息topicQueueTable

/**
 * 消息隊列路由信息；key為topic，value為QueueData
 */
private final HashMap<String/* topic */, List<QueueData>> topicQueueTable;

public class QueueData implements Comparable<QueueData> {
    /**
     * Broker名稱
     */
    private String brokerName;
    /**
     * 讀隊列個數，默認4個
     */
    private int readQueueNums;
    /**
     * 寫隊列個數，默認4個
     */
    private int writeQueueNums;
    /**
     * 隊列權限
     */
    private int perm;
    /**
     * 配置的,同步復制還是異步復制標記,對應TopicConfig.topicSysFlag
     *
     */
    private int topicSynFlag;
}

/**
 * Broker狀態信息，NameServer每次收到心跳包會替換該信息，每隔30秒更新一次
 * brokerAddr: ip:port->{}
 */
private final HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;

class BrokerLiveInfo {
    /**
     * 存儲上次收到心跳包的時間,每隔30秒更新一次
     */
    private long lastUpdateTimestamp;
    private DataVersion dataVersion;
    private Channel channel;
    private String haServerAddr;
}

NamesrvStartup.java 啟動入口類，NameServer 啟動默認端口9876

nettyServerConfig.setListenPort(9876)

每10秒鐘掃描一次，移除失效的broker，同時刪除緩存元數據信息

//初始化NameServer
boolean initResult = controller.initialize();
public boolean initialize() {
    //加載KV配置
    this.kvConfigManager.load();

    this.remotingServer = new NettyRemotingServer(this.nettyServerConfig, this.brokerHousekeepingService);

    this.remotingExecutor =
        Executors.newFixedThreadPool(nettyServerConfig.getServerWorkerThreads(), new ThreadFactoryImpl("RemotingExecutorThread_"));

    this.registerProcessor();
    //每10秒鐘掃描一次，移除失效的broker
    this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {

        @Override
        public void run() {
            NamesrvController.this.routeInfoManager.scanNotActiveBroker();
        }
    }, 5, 10, TimeUnit.SECONDS);
    //每隔10秒鐘打印一次KV配置信息
    this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {

        @Override
        public void run() {
            NamesrvController.this.kvConfigManager.printAllPeriodically();
        }
    }, 1, 10, TimeUnit.MINUTES);

    return true;
}

失效時間為2分鐘，即：Broker在2分鐘內未上報心跳會被移除

/**
 * 失效時間為2分鐘，即：Broker在2分鐘內未上報心跳會被移除
 */
public void scanNotActiveBroker() {
    Iterator<Entry<String, BrokerLiveInfo>> it = this.brokerLiveTable.entrySet().iterator();
    while (it.hasNext()) {
        Entry<String, BrokerLiveInfo> next = it.next();
        long last = next.getValue().getLastUpdateTimestamp();
        if ((last + BROKER_CHANNEL_EXPIRED_TIME) < System.currentTimeMillis()) {
            RemotingUtil.closeChannel(next.getValue().getChannel());
            it.remove();
            log.warn("The broker channel expired, {} {}ms", next.getKey(), BROKER_CHANNEL_EXPIRED_TIME);
            this.onChannelDestroy(next.getKey(), next.getValue().getChannel());
        }
    }
}
private final static long BROKER_CHANNEL_EXPIRED_TIME = 1000 * 60 * 2;

2.DefaultRequestProcessor

用於響應客戶端、Broker的請求。主要向NameServer發送心跳包、獲取Cluster、Broker、Topic元數據信息。
調用鏈：
在NameServer啟動時註冊，NamesrvController.initialize()->registerProcessor()

public RemotingCommand processRequest(ChannelHandlerContext ctx, RemotingCommand request) throws RemotingCommandException {
    if (log.isDebugEnabled()) {
        log.debug("receive request, {} {} {}",
            request.getCode(),
            RemotingHelper.parseChannelRemoteAddr(ctx.channel()),
            request);
    }

    switch (request.getCode()) {
        case RequestCode.PUT_KV_CONFIG://增加NameServer配置信息；由DefaultMQAdminExt使用
            return this.putKVConfig(ctx, request);
        case RequestCode.GET_KV_CONFIG://根據NameSpace和key獲取NameServer配置信息；由DefaultMQAdminExt使用
            return this.getKVConfig(ctx, request);
        case RequestCode.DELETE_KV_CONFIG: //據NameSapce和Key刪除NameServerr配置信息
            return this.deleteKVConfig(ctx, request);
        case RequestCode.REGISTER_BROKER: //註冊Broker信息；由BrokerOuterAPI.registerBroker使用，在BrokerController啟動時調用
            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);
            }
        case RequestCode.UNREGISTER_BROKER://移除註銷broker信息；由BrokerOuterAPI.unregisterBroker使用，在BrokerController.shutdown時調用
            return this.unregisterBroker(ctx, request);
        case RequestCode.GET_ROUTEINTO_BY_TOPIC: //獲取Topic路由信息 TopicRouteData
            return this.getRouteInfoByTopic(ctx, request);
        case RequestCode.GET_BROKER_CLUSTER_INFO://獲取Cluster及Broker信息
            return this.getBrokerClusterInfo(ctx, request);
        case RequestCode.WIPE_WRITE_PERM_OF_BROKER: //去除該broker上所有topic的寫權限
            return this.wipeWritePermOfBroker(ctx, request);
        case RequestCode.GET_ALL_TOPIC_LIST_FROM_NAMESERVER: //獲取所有的Topic列表
            return getAllTopicListFromNameserver(ctx, request);
        case RequestCode.DELETE_TOPIC_IN_NAMESRV: //從nameServer中刪除topic
            return deleteTopicInNamesrv(ctx, request);
        case RequestCode.GET_KVLIST_BY_NAMESPACE: //獲取配置信息 configTable
            return this.getKVListByNamespace(ctx, request);
        case RequestCode.GET_TOPICS_BY_CLUSTER: //獲取該集群下的所有topic list
            return this.getTopicsByCluster(ctx, request);
        case RequestCode.GET_SYSTEM_TOPIC_LIST_FROM_NS: // 此處意思為：系統會將集群名稱、broker名稱作為默認topic創建。現在獲取這類topic
            return this.getSystemTopicListFromNs(ctx, request);
        case RequestCode.GET_UNIT_TOPIC_LIST: //暫無使用
            return this.getUnitTopicList(ctx, request);
        case RequestCode.GET_HAS_UNIT_SUB_TOPIC_LIST: //暫無使用
            return this.getHasUnitSubTopicList(ctx, request);
        case RequestCode.GET_HAS_UNIT_SUB_UNUNIT_TOPIC_LIST://暫無使用
            return this.getHasUnitSubUnUnitTopicList(ctx, request);
        case RequestCode.UPDATE_NAMESRV_CONFIG: //更新properties請求
            return this.updateConfig(ctx, request);
        case RequestCode.GET_NAMESRV_CONFIG: //獲取properties內容
            return this.getConfig(ctx, request);
        default:
            break;
    }
    return null;
}

註冊broker信息

Broker每隔30秒向所有的NameServer上報Topic註冊信息
Broker調用鏈

  BrokerController.start()->this.registerBrokerAll()->this.brokerOuterAPI.registerBrokerAll()

//每隔30秒向所有的NameServer上報Topic註冊信息
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {

    @Override
    public void run() {
        try {
            BrokerController.this.registerBrokerAll(true, false);
        } catch (Throwable e) {
            log.error("registerBrokerAll Exception", e);
        }
    }
}, 1000 * 10, 1000 * 30, TimeUnit.MILLISECONDS);

服務端處理主要包括：註冊集群信息clusterAddrTable、註冊broker信息brokerAddrTable、
註冊topic信息topicQueueTable、broker心跳包brokerLiveTable
NameServer處理鏈

  DefaultRequestProcessor->processRequest->RequestCode.REGISTER_BROKER->this.registerBroker->RouteInfoManager.registerBroker()

public RegisterBrokerResult registerBroker(
    final String clusterName,
    final String brokerAddr,
    final String brokerName,
    final long brokerId,
    final String haServerAddr,
    final TopicConfigSerializeWrapper topicConfigWrapper,
    final List<String> filterServerList,
    final Channel channel) {
    RegisterBrokerResult result = new RegisterBrokerResult();
    try {
        try {
            //加寫鎖，防止並發修改
            this.lock.writeLock().lockInterruptibly();
            //註冊集群信息
            Set<String> brokerNames = this.clusterAddrTable.get(clusterName);
            if (null == brokerNames) {
                brokerNames = new HashSet<String>();
                this.clusterAddrTable.put(clusterName, brokerNames);
            }
            brokerNames.add(brokerName);

            boolean registerFirst = false;
            //註冊broker信息
            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);
            }
            String oldAddr = brokerData.getBrokerAddrs().put(brokerId, brokerAddr);
            registerFirst = registerFirst || (null == oldAddr);
            //Topic配置變化了；Master Broker第一次註冊或者Topic dataVersion不相同時更新路由信息
            //有Topic新增時dataVersion會遞增
            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()) {
                            this.createAndUpdateQueueData(brokerName, entry.getValue()); //更新topicQueueTable
                        }
                    }
                }
            }
            //更新broker心跳信息
            BrokerLiveInfo prevBrokerLiveInfo = this.brokerLiveTable.put(brokerAddr,
                new BrokerLiveInfo(
                    System.currentTimeMillis(),
                    topicConfigWrapper.getDataVersion(),
                    channel,
                    haServerAddr));
            //新broker註冊時會有日誌輸出
            if (null == prevBrokerLiveInfo) {
                log.info("new broker registerd, {} HAServer: {}", brokerAddr, haServerAddr);
            }
            //更新filterServer信息
            if (filterServerList != null) {
                if (filterServerList.isEmpty()) {
                    this.filterServerTable.remove(brokerAddr);
                } else {
                    this.filterServerTable.put(brokerAddr, filterServerList);
                }
            }
            //Slave設置MasterAddr和HaServerAddr
            if (MixAll.MASTER_ID != brokerId) {
                String masterAddr = brokerData.getBrokerAddrs().get(MixAll.MASTER_ID);
                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;
}

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