NameServer
概述
Name server主要负责对于源数据的管理，包括了对于Topic和路由信息的管理，Broker在启动的时候会去向Name server注册并且定时发送心跳，Producer在启动的时候会到Name server上去拉取Topic所属的broker具体地址，然后向具体的broker发送消息。
特点
Name Server是一个几乎无状态的结点，Name Server之间采取share-nothing的设计，互不通信。
对于一个Name Server集群列表，客户端连接Name Server的时候，只会选择随机连接一个结点，以做到负载均衡。
Name Server所有状态都从Broker上报而来，本身不存储任何状态，所有数据均在内存。
如果中途所有Name Server全都挂了，影响到路由信息的更新，不会影响和Broker的通信。
源码阅读
核心类
NamesrvStartUp：启动类
NamesrvController：管理类，控制NameServer的生命周期
RouteInfoManager：路由信息管理类，管理topic队列信息、broker地址信息、集群信息等
DefaultRequestProcessosr：请求处理类，处理网络请求，broker注册
数据结构
//topic对应broker的信息
HashMap<String/* topic */, List<QueueData>> topicQueueTable;
//保存同意brokerName下的broker集群信息
HashMap<String/* brokerName */, BrokerData> brokerAddrTable;
//保存集群下的broker名称
HashMap<String/* clusterName */, Set<String/* brokerName */>> clusterAddrTable;
//保存broker的版本信息，连接信息，上次更新时间
HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;
//保存broker过滤服务的信息
HashMap<String/* brokerAddr */, List<String>/* Filter Server */> filterServerTable;NamesrvStartup
public static NamesrvController main0(String[] args) {
System.setProperty(RemotingCommand.REMOTING_VERSION_KEY, Integer.toString(MQVersion.CURRENT_VERSION));
try {
//PackageConflictDetect.detectFastjson();
//解析命令行
Options options = ServerUtil.buildCommandlineOptions(new Options());
commandLine = ServerUtil.parseCmdLine("mqnamesrv", args, buildCommandlineOptions(options), new PosixParser());
if (null == commandLine) {
System.exit(-1);
return null;
}
//初始化配置
final NamesrvConfig namesrvConfig = new NamesrvConfig();
final NettyServerConfig nettyServerConfig = new NettyServerConfig();
nettyServerConfig.setListenPort(9876);
if (commandLine.hasOption('c')) {
String file = commandLine.getOptionValue('c');
if (file != null) {
InputStream in = new BufferedInputStream(new FileInputStream(file));
properties = new Properties();
properties.load(in);
MixAll.properties2Object(properties, namesrvConfig);
MixAll.properties2Object(properties, nettyServerConfig);
namesrvConfig.setConfigStorePath(file);
System.out.printf("load config properties file OK, " + file + "%n");
in.close();
}
}
if (commandLine.hasOption('p')) {
MixAll.printObjectProperties(null, namesrvConfig);
MixAll.printObjectProperties(null, nettyServerConfig);
System.exit(0);
}
MixAll.properties2Object(ServerUtil.commandLine2Properties(commandLine), namesrvConfig);
if (null == namesrvConfig.getRocketmqHome()) { //检查环境变量
System.out.printf("Please set the %s variable in your environment to match the location of the RocketMQ installation%n", MixAll.ROCKETMQ_HOME_ENV);
System.exit(-2);
}
LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory();
JoranConfigurator configurator = new JoranConfigurator();
configurator.setContext(lc);
lc.reset();
configurator.doConfigure(namesrvConfig.getRocketmqHome() + "/conf/logback_namesrv.xml");
final Logger log = LoggerFactory.getLogger(LoggerName.NAMESRV_LOGGER_NAME);
MixAll.printObjectProperties(log, namesrvConfig);
MixAll.printObjectProperties(log, nettyServerConfig);
final NamesrvController controller = new NamesrvController(namesrvConfig, nettyServerConfig);
// remember all configs to prevent discard
controller.getConfiguration().registerConfig(properties);
boolean initResult = controller.initialize();
if (!initResult) {
controller.shutdown();
System.exit(-3);
}
//钩子，关闭
Runtime.getRuntime().addShutdownHook(new ShutdownHookThread(log, new Callable<Void>() {
@Override
public Void call() throws Exception {
controller.shutdown();
return null;
}
}));
//启动服务，remotingServer.start()
controller.start();
String tip = "The Name Server boot success. serializeType=" + RemotingCommand.getSerializeTypeConfigInThisServer();
log.info(tip);
System.out.printf(tip + "%n");
return controller;
} catch (Throwable e) {
e.printStackTrace();
System.exit(-1);
}
return null;
}NamesrvController
public boolean initialize() {
//加载配置到configtable中
//HashMap<String/* Namespace */, HashMap<String/* Key */, String/* Value */>> configTable
this.kvConfigManager.load();
//初始化路由服务
//详情请查看路由模块的源码
this.remotingServer = new NettyRemotingServer(this.nettyServerConfig, this.brokerHousekeepingService);
//remote线程池
this.remotingExecutor =
Executors.newFixedThreadPool(nettyServerConfig.getServerWorkerThreads(), new ThreadFactoryImpl("RemotingExecutorThread_"));
//注册处理类
this.registerProcessor();
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
//定时关闭超时的连接
NamesrvController.this.routeInfoManager.scanNotActiveBroker();
}
}, 5, 10, TimeUnit.SECONDS);
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
//定期输出配置表中的信息
NamesrvController.this.kvConfigManager.printAllPeriodically();
}
}, 1, 10, TimeUnit.MINUTES);
return true;
}private void registerProcessor() {
if (namesrvConfig.isClusterTest()) {
this.remotingServer.registerDefaultProcessor(new ClusterTestRequestProcessor(this, namesrvConfig.getProductEnvName()),
this.remotingExecutor);
} else {
// new Pair<NettyRequestProcessor, ExecutorService>
this.remotingServer.registerDefaultProcessor(new DefaultRequestProcessor(this), this.remotingExecutor);
}
}public void start() throws Exception {
this.remotingServer.start();
}public void shutdown() {
this.remotingServer.shutdown();
this.remotingExecutor.shutdown();
this.scheduledExecutorService.shutdown();
}DefaultRequestProcessosr
public RemotingCommand processRequest(ChannelHandlerContext ctx,
RemotingCommand request) throws RemotingCommandException {
if (log.isDebugEnabled()) {
log.debug("receive request, {} {} {}",
request.getCode(),
RemotingHelper.parseChannelRemoteAddr(ctx.channel()),
request);
}
//根据不同的请求类型，执行不同的操作
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.REGISTER_BROKER: //注册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);
}
case RequestCode.UNREGISTER_BROKER: //注销broker
return this.unregisterBroker(ctx, request);
case RequestCode.GET_ROUTEINTO_BY_TOPIC: //获取topic信息
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);
case RequestCode.UPDATE_NAMESRV_CONFIG:
return this.updateConfig(ctx, request);
case RequestCode.GET_NAMESRV_CONFIG:
return this.getConfig(ctx, request);
default:
break;
}
return null;
}RouteInfoManager
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 {
//加写锁
this.lock.writeLock().lockInterruptibly();
Set<String> brokerNames = this.clusterAddrTable.get(clusterName);
if (null == brokerNames) {
brokerNames = new HashSet<String>();
this.clusterAddrTable.put(clusterName, brokerNames);
}
brokerNames.add(brokerName);
//是否是第一次注册
boolean registerFirst = false;
BrokerData brokerData = this.brokerAddrTable.get(brokerName);
if (null == brokerData) { //是第一次注册，创建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);
if (null != topicConfigWrapper
&& MixAll.MASTER_ID == brokerId) {
//topicConfig包装类不为空，并且注册的broker是主节点(brokerId=0)
if (this.isBrokerTopicConfigChanged(brokerAddr, topicConfigWrapper.getDataVersion())
|| registerFirst) {
ConcurrentMap<String, TopicConfig> tcTable =
topicConfigWrapper.getTopicConfigTable();
if (tcTable != null) {
for (Map.Entry<String, TopicConfig> entry : tcTable.entrySet()) {
//更新topic队列信息
this.createAndUpdateQueueData(brokerName, entry.getValue());
}
}
}
}
//更新存活broker表中
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);
}
if (filterServerList != null) {
if (filterServerList.isEmpty()) {
this.filterServerTable.remove(brokerAddr);
} else {
this.filterServerTable.put(brokerAddr, filterServerList);
}
}
if (MixAll.MASTER_ID != brokerId) { //如果注册的broker是从节点
String masterAddr = brokerData.getBrokerAddrs().get(MixAll.MASTER_ID);
if (masterAddr != null) {
BrokerLiveInfo brokerLiveInfo = this.brokerLiveTable.get(masterAddr);
if (brokerLiveInfo != null) { //返回主节点信息
result.setHaServerAddr(brokerLiveInfo.getHaServerAddr());
result.setMasterAddr(masterAddr);
}
}
}
} finally {
//是否写锁
this.lock.writeLock().unlock();
}
} catch (Exception e) {
log.error("registerBroker Exception", e);
}
return result;
}Last updated