RocketMQ Namesrv架構工作原理詳解

2022-08-10 18:01:40

1 概念

Namesrv的作用是儲存後設資料，提高Broker的可用性。

Namesrv的主要功能是臨時儲存，管理Topic路由資訊，各個Namesrv節點之間是不通訊，無狀態的，互相不知道對方的存在。

當Broker，生產者，消費者啟動的時候，會輪詢全部的Namesrv節點，獲取路由資訊。

2 核心資料結構和API

2.1 Namesrv的核心資料結構

Namesrv中儲存的資訊是Topic的路由資訊，Topic的路由決定了Topic的資訊傳送給哪些Broker，或者從哪些Broker獲取訊息。

路由資料結構的實現程式碼都在org.apache.rocketmq.namesrv.routeinfo.RouteInfoManager中

public class RouteInfoManager {
    private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.NAMESRV_LOGGER_NAME);
    //Broker存活的時間週期，預設120秒
    private final static long DEFAULT_BROKER_CHANNEL_EXPIRED_TIME = 1000 * 60 * 2;
    private final ReadWriteLock lock = new ReentrantReadWriteLock();
    //儲存Topic和佇列的路由資訊
    private final Map<String/* topic */, Map<String, QueueData>> topicQueueTable;
    //Broker名字和Broker資訊的對應資訊
    private final Map<String/* brokerName */, BrokerData> brokerAddrTable;
    //叢集和Broker的對應關係
    private final Map<String/* clusterName */, Set<String/* brokerName */>> clusterAddrTable;
    //線上的Broker地址和Broker資訊的對應關係
    private final Map<BrokerAddrInfo/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;
    //過濾伺服器訊息
    private final Map<BrokerAddrInfo/* brokerAddr */, List<String>/* Filter Server */> filterServerTable;
    private final Map<String/* topic */, Map<String/*brokerName*/, TopicQueueMappingInfo>> topicQueueMappingInfoTable;
    private final BatchUnRegisterService unRegisterService;
    private final NamesrvController namesrvController;
    private final NamesrvConfig namesrvConfig;

2.2 Namesrv的API

Namesrv的的API在org.apache.rocketmq.namesrv.processor.DefaultRequestProcessor中，根據方法名很容易判斷出來方法的作用。

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 this.queryBrokerTopicConfig(ctx, request);
    case RequestCode.REGISTER_BROKER:
        //Broker註冊自身資訊到Namesrv
        return this.registerBroker(ctx, request);
    case RequestCode.UNREGISTER_BROKER:
        //Broker取消註冊自身資訊到Namesrv
        return this.unregisterBroker(ctx, request);
    case RequestCode.BROKER_HEARTBEAT:
        return this.brokerHeartbeat(ctx, request);
    case RequestCode.GET_BROKER_MEMBER_GROUP:
        return this.getBrokerMemberGroup(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.ADD_WRITE_PERM_OF_BROKER:
        return this.addWritePermOfBroker(ctx, request);
    case RequestCode.GET_ALL_TOPIC_LIST_FROM_NAMESERVER:
        return this.getAllTopicListFromNameserver(ctx, request);
    case RequestCode.DELETE_TOPIC_IN_NAMESRV:
        return this.deleteTopicInNamesrv(ctx, request);
    case RequestCode.REGISTER_TOPIC_IN_NAMESRV:
        return this.registerTopicToNamesrv(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);
    case RequestCode.UPDATE_NAMESRV_CONFIG:
        return this.updateConfig(ctx, request);
    case RequestCode.GET_NAMESRV_CONFIG:
        return this.getConfig(ctx, request);
    case RequestCode.GET_CLIENT_CONFIG:
        return this.getClientConfigs(ctx, request);
    default:
        String error = " request type " + request.getCode() + " not supported";
        return RemotingCommand.createResponseCommand(RemotingSysResponseCode.REQUEST_CODE_NOT_SUPPORTED, error);
}