在RocketMQ中，使用BrokerStartup作为启动类，相较于NameServer的启动，Broker作为RocketMQ的核心可复杂得多
主函数作为其启动的入口：
1 public static void main(String[] args) { 2 start(createBrokerController(args)); 3 }
首先通过createBrokerController方法生成Broker的控制器BrokerController
createBrokerController方法：
1 public static BrokerController createBrokerController(String[] args) { 2 System.setProperty(RemotingCommand.REMOTING_VERSION_KEY, Integer.toString(MQVersion.CURRENT_VERSION)); 3 4 if (null == System.getProperty(NettySystemConfig.COM_ROCKETMQ_REMOTING_SOCKET_SNDBUF_SIZE)) { 5 NettySystemConfig.socketSndbufSize = 131072; 6 } 7 8 if (null == System.getProperty(NettySystemConfig.COM_ROCKETMQ_REMOTING_SOCKET_RCVBUF_SIZE)) { 9 NettySystemConfig.socketRcvbufSize = 131072; 10 } 11 12 try { 13 //PackageConflictDetect.detectFastjson(); 14 Options options = ServerUtil.buildCommandlineOptions(new Options()); 15 commandLine = ServerUtil.parseCmdLine("mqbroker", args, buildCommandlineOptions(options), 16 new PosixParser()); 17 if (null == commandLine) { 18 System.exit(-1); 19 } 20 21 final BrokerConfig brokerConfig = new BrokerConfig(); 22 final NettyServerConfig nettyServerConfig = new NettyServerConfig(); 23 final NettyClientConfig nettyClientConfig = new NettyClientConfig(); 24 25 nettyClientConfig.setUseTLS(Boolean.parseBoolean(System.getProperty(TLS_ENABLE, 26 String.valueOf(TlsSystemConfig.tlsMode == TlsMode.ENFORCING)))); 27 nettyServerConfig.setListenPort(10911); 28 final MessageStoreConfig messageStoreConfig = new MessageStoreConfig(); 29 30 if (BrokerRole.SLAVE == messageStoreConfig.getBrokerRole()) { 31 int ratio = messageStoreConfig.getAccessMessageInMemoryMaxRatio() - 10; 32 messageStoreConfig.setAccessMessageInMemoryMaxRatio(ratio); 33 } 34 35 if (commandLine.hasOption('c')) { 36 String file = commandLine.getOptionValue('c'); 37 if (file != null) { 38 configFile = file; 39 InputStream in = new BufferedInputStream(new FileInputStream(file)); 40 properties = new Properties(); 41 properties.load(in); 42 43 properties2SystemEnv(properties); 44 MixAll.properties2Object(properties, brokerConfig); 45 MixAll.properties2Object(properties, nettyServerConfig); 46 MixAll.properties2Object(properties, nettyClientConfig); 47 MixAll.properties2Object(properties, messageStoreConfig); 48 49 BrokerPathConfigHelper.setBrokerConfigPath(file); 50 in.close(); 51 } 52 } 53 54 MixAll.properties2Object(ServerUtil.commandLine2Properties(commandLine), brokerConfig); 55 56 if (null == brokerConfig.getRocketmqHome()) { 57 System.out.printf("Please set the %s variable in your environment to match the location of the RocketMQ installation", MixAll.ROCKETMQ_HOME_ENV); 58 System.exit(-2); 59 } 60 61 String namesrvAddr = brokerConfig.getNamesrvAddr(); 62 if (null != namesrvAddr) { 63 try { 64 String[] addrArray = namesrvAddr.split(";"); 65 for (String addr : addrArray) { 66 RemotingUtil.string2SocketAddress(addr); 67 } 68 } catch (Exception e) { 69 System.out.printf( 70 "The Name Server Address[%s] illegal, please set it as follows, \"127.0.0.1:9876;192.168.0.1:9876\"%n", 71 namesrvAddr); 72 System.exit(-3); 73 } 74 } 75 76 switch (messageStoreConfig.getBrokerRole()) { 77 case ASYNC_MASTER: 78 case SYNC_MASTER: 79 brokerConfig.setBrokerId(MixAll.MASTER_ID); 80 break; 81 case SLAVE: 82 if (brokerConfig.getBrokerId() <= 0) { 83 System.out.printf("Slave's brokerId must be > 0"); 84 System.exit(-3); 85 } 86 87 break; 88 default: 89 break; 90 } 91 92 messageStoreConfig.setHaListenPort(nettyServerConfig.getListenPort() + 1); 93 LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory(); 94 JoranConfigurator configurator = new JoranConfigurator(); 95 configurator.setContext(lc); 96 lc.reset(); 97 configurator.doConfigure(brokerConfig.getRocketmqHome() + "/conf/logback_broker.xml"); 98 99 if (commandLine.hasOption('p')) { 100 InternalLogger console = InternalLoggerFactory.getLogger(LoggerName.BROKER_CONSOLE_NAME); 101 MixAll.printObjectProperties(console, brokerConfig); 102 MixAll.printObjectProperties(console, nettyServerConfig); 103 MixAll.printObjectProperties(console, nettyClientConfig); 104 MixAll.printObjectProperties(console, messageStoreConfig); 105 System.exit(0); 106 } else if (commandLine.hasOption('m')) { 107 InternalLogger console = InternalLoggerFactory.getLogger(LoggerName.BROKER_CONSOLE_NAME); 108 MixAll.printObjectProperties(console, brokerConfig, true); 109 MixAll.printObjectProperties(console, nettyServerConfig, true); 110 MixAll.printObjectProperties(console, nettyClientConfig, true); 111 MixAll.printObjectProperties(console, messageStoreConfig, true); 112 System.exit(0); 113 } 114 115 log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME); 116 MixAll.printObjectProperties(log, brokerConfig); 117 MixAll.printObjectProperties(log, nettyServerConfig); 118 MixAll.printObjectProperties(log, nettyClientConfig); 119 MixAll.printObjectProperties(log, messageStoreConfig); 120 121 final BrokerController controller = new BrokerController( 122 brokerConfig, 123 nettyServerConfig, 124 nettyClientConfig, 125 messageStoreConfig); 126 // remember all configs to prevent discard 127 controller.getConfiguration().registerConfig(properties); 128 129 boolean initResult = controller.initialize(); 130 if (!initResult) { 131 controller.shutdown(); 132 System.exit(-3); 133 } 134 135 Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() { 136 private volatile boolean hasShutdown = false; 137 private AtomicInteger shutdownTimes = new AtomicInteger(0); 138 139 @Override 140 public void run() { 141 synchronized (this) { 142 log.info("Shutdown hook was invoked, {}", this.shutdownTimes.incrementAndGet()); 143 if (!this.hasShutdown) { 144 this.hasShutdown = true; 145 long beginTime = System.currentTimeMillis(); 146 controller.shutdown(); 147 long consumingTimeTotal = System.currentTimeMillis() - beginTime; 148 log.info("Shutdown hook over, consuming total time(ms): {}", consumingTimeTotal); 149 } 150 } 151 } 152 }, "ShutdownHook")); 153 154 return controller; 155 } catch (Throwable e) { 156 e.printStackTrace(); 157 System.exit(-1); 158 } 159 160 return null; 161 }
这里和NameServer中的createNamesrvController方法作用类似，对Broker所需做了一系列的配置
先设置了Netty通信时的缓冲区大小，这里默认是128K
接着会创建了几个实体类
BrokerConfig，用来封装其绝大多数基本配置信息
NettyServerConfig，封装了其作为对外暴露的消息队列服务器的信息
NettyClientConfig，则封装了其作为NameServer客户端的信息
这里面封装的信息和NameServer一个道理，都是映射了配置文件相应的配置
然后对NettyClientConfig的TLS进行设置
让NettyServerConfig默认监听10911端口
紧接着创建了一个MessageStoreConfig，这个就是用来封装Store的信息，
MessageStoreConfig会默认配置BrokerRole为ASYNC_MASTER
Broker有三种身份，用BrokerRole枚举来表示：
1 public enum BrokerRole { 2 ASYNC_MASTER, 3 SYNC_MASTER, 4 SLAVE; 5 }
也就是异步Master，同步Master，以及Slave
这里会对其身份进行检查，若是Slave，则需要调整其允许的消息最大内存占比，默认值是40，也就是说Master允许消息最大内存占用40%，而Slave则只允许30%
接着会对”-c“指令进行相应配置的加载
往后看到对namesrvAddr进行了检查，只是简单地检查NameServer集群地址信息是否合法
往下看到有个switch块，其根据Broker的身份，进行设置
只要是Master，将其BrokerId设为0，而Slave的BrokerId需要大于0
（一个Master可以对应多个Slave，但是一个Slave只能对应一个Master，Master与Slave的对应关系通过指定相同的BrokerName，不同的BrokerId来定义，BrokerId为0表示Master，大于0表示Slave，Master也可以部署多个）
继续往下，这里会对Store设置HA的监听端口，是NettyServer侦听端口加1
往下是对“-p”，”-m“指令进行相应配置的加载，以及日志的相关配置
之后就会创建了一个BrokerController：
1 public BrokerController( 2 final BrokerConfig brokerConfig, 3 final NettyServerConfig nettyServerConfig, 4 final NettyClientConfig nettyClientConfig, 5 final MessageStoreConfig messageStoreConfig 6 ) { 7 this.brokerConfig = brokerConfig; 8 this.nettyServerConfig = nettyServerConfig; 9 this.nettyClientConfig = nettyClientConfig; 10 this.messageStoreConfig = messageStoreConfig; 11 this.consumerOffsetManager = new ConsumerOffsetManager(this); 12 this.topicConfigManager = new TopicConfigManager(this); 13 this.pullMessageProcessor = new PullMessageProcessor(this); 14 this.pullRequestHoldService = new PullRequestHoldService(this); 15 this.messageArrivingListener = new NotifyMessageArrivingListener(this.pullRequestHoldService); 16 this.consumerIdsChangeListener = new DefaultConsumerIdsChangeListener(this); 17 this.consumerManager = new ConsumerManager(this.consumerIdsChangeListener); 18 this.consumerFilterManager = new ConsumerFilterManager(this); 19 this.producerManager = new ProducerManager(); 20 this.clientHousekeepingService = new ClientHousekeepingService(this); 21 this.broker2Client = new Broker2Client(this); 22 this.subscriptionGroupManager = new SubscriptionGroupManager(this); 23 this.brokerOuterAPI = new BrokerOuterAPI(nettyClientConfig); 24 this.filterServerManager = new FilterServerManager(this); 25 26 this.slaveSynchronize = new SlaveSynchronize(this); 27 28 this.sendThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getSendThreadPoolQueueCapacity()); 29 this.pullThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getPullThreadPoolQueueCapacity()); 30 this.queryThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getQueryThreadPoolQueueCapacity()); 31 this.clientManagerThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getClientManagerThreadPoolQueueCapacity()); 32 this.consumerManagerThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getConsumerManagerThreadPoolQueueCapacity()); 33 this.heartbeatThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getHeartbeatThreadPoolQueueCapacity()); 34 this.endTransactionThreadPoolQueue = new LinkedBlockingQueue<Runnable>(this.brokerConfig.getEndTransactionPoolQueueCapacity()); 35 36 this.brokerStatsManager = new BrokerStatsManager(this.brokerConfig.getBrokerClusterName()); 37 this.setStoreHost(new InetSocketAddress(this.getBrokerConfig().getBrokerIP1(), this.getNettyServerConfig().getListenPort())); 38 39 this.brokerFastFailure = new BrokerFastFailure(this); 40 this.configuration = new Configuration( 41 log, 42 BrokerPathConfigHelper.getBrokerConfigPath(), 43 this.brokerConfig, this.nettyServerConfig, this.nettyClientConfig, this.messageStoreConfig 44 ); 45 }
可以看到，这里实例化了许多成员，我就不一一分析，挑几个重要的介绍
ConsumerOffsetManager：用来管理消费者的消费消息的进度，主要通过一张map来缓存
1 private ConcurrentMap<String/* topic@group */, ConcurrentMap<Integer, Long>> offsetTable = 2 new ConcurrentHashMap<String, ConcurrentMap<Integer, Long>>(512);
由topic@group的形式构成键，而值中的map的Integer代表具体的哪条消息队列，Long表示该消息队列的偏移量offset
TopicConfigManager：管理Topic和消息队列的信息，主要通过一张map来缓存
1 private final ConcurrentMap<String, TopicConfig> topicConfigTable = 2 new ConcurrentHashMap<String, TopicConfig>(1024); 3 private final DataVersion dataVersion = new DataVersion();
键就是Topic，值TopicConfig用来记录对应的消息队列的个数
PullMessageProcessor、PullRequestHoldService、NotifyMessageArrivingListener这三个来管理Pull消息请求，关于Pull消息在后续博客再细说
ConsumerManager：管理Consumer，主要通过一张map来缓存
1 private final ConcurrentMap<String/* Group */, ConsumerGroupInfo> consumerTable = 2 new ConcurrentHashMap<String, ConsumerGroupInfo>(1024);
键值就是Consumer的GroupName，
而ConsumerGroupInfo由如下构成：
1 private final ConcurrentMap<String/* Topic */, SubscriptionData> subscriptionTable = 2 new ConcurrentHashMap<String, SubscriptionData>(); 3 private final ConcurrentMap<Channel, ClientChannelInfo> channelInfoTable = 4 new ConcurrentHashMap<Channel, ClientChannelInfo>(16); 5 private volatile ConsumeType consumeType; 6 private volatile MessageModel messageModel;
可以看到封装了一个subscriptionTable ，这个map记录Topic和订阅内容
以及一个channelInfoTable，记录Consumer的物理连接
ConsumeType是一个枚举，表明两种消费方式：
1 public enum ConsumeType { 2 CONSUME_ACTIVELY("PULL"), 3 CONSUME_PASSIVELY("PUSH"); 4 }
MessageModel 也是一个枚举，表明两种消费模式：
1 public enum MessageModel { 2 /** 3 * broadcast 4 */ 5 BROADCASTING("BROADCASTING"), 6 /** 7 * clustering 8 */ 9 CLUSTERING("CLUSTERING"); 10 }
Broadcasting：同一个ConsumerGroup里的每个Consumer都能消费到所订阅Topic的全部消息，也就是一个消息会被多次分发，被多个Consumer消费
Clustering：同一个ConsumerGroup里的每个Consumer只消费所订阅消息的一部分内容，同一个ConsumerGroup里所有的Consumer消费的内容合起来才是所订阅Topic内容的整体，从而达到负载均衡的目的
结合着来看，也就是说使用相同GroupName的一组Consumer，其ConsumeType和MessageModel必定相同，其订阅的Topic会根据ConsumeType和MessageModel来完成相应的方式的消息处理
回到BrokerController的构造
ProducerManager：管理Producer，主要通过一张map来缓存
1 private final HashMap<String /* group name */, HashMap<Channel, ClientChannelInfo>> groupChannelTable = 2 new HashMap<String, HashMap<Channel, ClientChannelInfo>>();
相比ConsumerManager，对Producer的管理简单的多，只需要记录group name 和物理连接的映射
再回到createBrokerController方法，在完成BrokerController的创建后，会调用BrokerController的initialize方法：
BrokerController的initialize方法：
1 public boolean initialize() throws CloneNotSupportedException { 2 boolean result = this.topicConfigManager.load(); 3 4 result = result && this.consumerOffsetManager.load(); 5 result = result && this.subscriptionGroupManager.load(); 6 result = result && this.consumerFilterManager.load(); 7 8 if (result) { 9 try { 10 this.messageStore = 11 new DefaultMessageStore(this.messageStoreConfig, this.brokerStatsManager, this.messageArrivingListener, 12 this.brokerConfig); 13 if (messageStoreConfig.isEnableDLegerCommitLog()) { 14 DLedgerRoleChangeHandler roleChangeHandler = new DLedgerRoleChangeHandler(this, (DefaultMessageStore) messageStore); 15 ((DLedgerCommitLog)((DefaultMessageStore) messageStore).getCommitLog()).getdLedgerServer().getdLedgerLeaderElector().addRoleChangeHandler(roleChangeHandler); 16 } 17 this.brokerStats = new BrokerStats((DefaultMessageStore) this.messageStore); 18 //load plugin 19 MessageStorePluginContext context = new MessageStorePluginContext(messageStoreConfig, brokerStatsManager, messageArrivingListener, brokerConfig); 20 this.messageStore = MessageStoreFactory.build(context, this.messageStore); 21 this.messageStore.getDispatcherList().addFirst(new CommitLogDispatcherCalcBitMap(this.brokerConfig, this.consumerFilterManager)); 22 } catch (IOException e) { 23 result = false; 24 log.error("Failed to initialize", e); 25 } 26 } 27 28 result = result && this.messageStore.load(); 29 30 if (result) { 31 this.remotingServer = new NettyRemotingServer(this.nettyServerConfig, this.clientHousekeepingService); 32 NettyServerConfig fastConfig = (NettyServerConfig) this.nettyServerConfig.clone(); 33 fastConfig.setListenPort(nettyServerConfig.getListenPort() - 2); 34 this.fastRemotingServer = new NettyRemotingServer(fastConfig, this.clientHousekeepingService); 35 this.sendMessageExecutor = new BrokerFixedThreadPoolExecutor( 36 this.brokerConfig.getSendMessageThreadPoolNums(), 37 this.brokerConfig.getSendMessageThreadPoolNums(), 38 1000 * 60, 39 TimeUnit.MILLISECONDS, 40 this.sendThreadPoolQueue, 41 new ThreadFactoryImpl("SendMessageThread_")); 42 43 this.pullMessageExecutor = new BrokerFixedThreadPoolExecutor( 44 this.brokerConfig.getPullMessageThreadPoolNums(), 45 this.brokerConfig.getPullMessageThreadPoolNums(), 46 1000 * 60, 47 TimeUnit.MILLISECONDS, 48 this.pullThreadPoolQueue, 49 new ThreadFactoryImpl("PullMessageThread_")); 50 51 this.queryMessageExecutor = new BrokerFixedThreadPoolExecutor( 52 this.brokerConfig.getQueryMessageThreadPoolNums(), 53 this.brokerConfig.getQueryMessageThreadPoolNums(), 54 1000 * 60, 55 TimeUnit.MILLISECONDS, 56 this.queryThreadPoolQueue, 57 new ThreadFactoryImpl("QueryMessageThread_")); 58 59 this.adminBrokerExecutor = 60 Executors.newFixedThreadPool(this.brokerConfig.getAdminBrokerThreadPoolNums(), new ThreadFactoryImpl( 61 "AdminBrokerThread_")); 62 63 this.clientManageExecutor = new ThreadPoolExecutor( 64 this.brokerConfig.getClientManageThreadPoolNums(), 65 this.brokerConfig.getClientManageThreadPoolNums(), 66 1000 * 60, 67 TimeUnit.MILLISECONDS, 68 this.clientManagerThreadPoolQueue, 69 new ThreadFactoryImpl("ClientManageThread_")); 70 71 this.heartbeatExecutor = new BrokerFixedThreadPoolExecutor( 72 this.brokerConfig.getHeartbeatThreadPoolNums(), 73 this.brokerConfig.getHeartbeatThreadPoolNums(), 74 1000 * 60, 75 TimeUnit.MILLISECONDS, 76 this.heartbeatThreadPoolQueue, 77 new ThreadFactoryImpl("HeartbeatThread_", true)); 78 79 this.endTransactionExecutor = new BrokerFixedThreadPoolExecutor( 80 this.brokerConfig.getEndTransactionThreadPoolNums(), 81 this.brokerConfig.getEndTransactionThreadPoolNums(), 82 1000 * 60, 83 TimeUnit.MILLISECONDS, 84 this.endTransactionThreadPoolQueue, 85 new ThreadFactoryImpl("EndTransactionThread_")); 86 87 this.consumerManageExecutor = 88 Executors.newFixedThreadPool(this.brokerConfig.getConsumerManageThreadPoolNums(), new ThreadFactoryImpl( 89 "ConsumerManageThread_")); 90 91 this.registerProcessor(); 92 93 final long initialDelay = UtilAll.computNextMorningTimeMillis() - System.currentTimeMillis(); 94 final long period = 1000 * 60 * 60 * 24; 95 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 96 @Override 97 public void run() { 98 try { 99 BrokerController.this.getBrokerStats().record(); 100 } catch (Throwable e) { 101 log.error("schedule record error.", e); 102 } 103 } 104 }, initialDelay, period, TimeUnit.MILLISECONDS); 105 106 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 107 @Override 108 public void run() { 109 try { 110 BrokerController.this.consumerOffsetManager.persist(); 111 } catch (Throwable e) { 112 log.error("schedule persist consumerOffset error.", e); 113 } 114 } 115 }, 1000 * 10, this.brokerConfig.getFlushConsumerOffsetInterval(), TimeUnit.MILLISECONDS); 116 117 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 118 @Override 119 public void run() { 120 try { 121 BrokerController.this.consumerFilterManager.persist(); 122 } catch (Throwable e) { 123 log.error("schedule persist consumer filter error.", e); 124 } 125 } 126 }, 1000 * 10, 1000 * 10, TimeUnit.MILLISECONDS); 127 128 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 129 @Override 130 public void run() { 131 try { 132 BrokerController.this.protectBroker(); 133 } catch (Throwable e) { 134 log.error("protectBroker error.", e); 135 } 136 } 137 }, 3, 3, TimeUnit.MINUTES); 138 139 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 140 @Override 141 public void run() { 142 try { 143 BrokerController.this.printWaterMark(); 144 } catch (Throwable e) { 145 log.error("printWaterMark error.", e); 146 } 147 } 148 }, 10, 1, TimeUnit.SECONDS); 149 150 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 151 152 @Override 153 public void run() { 154 try { 155 log.info("dispatch behind commit log {} bytes", BrokerController.this.getMessageStore().dispatchBehindBytes()); 156 } catch (Throwable e) { 157 log.error("schedule dispatchBehindBytes error.", e); 158 } 159 } 160 }, 1000 * 10, 1000 * 60, TimeUnit.MILLISECONDS); 161 162 if (this.brokerConfig.getNamesrvAddr() != null) { 163 this.brokerOuterAPI.updateNameServerAddressList(this.brokerConfig.getNamesrvAddr()); 164 log.info("Set user specified name server address: {}", this.brokerConfig.getNamesrvAddr()); 165 } else if (this.brokerConfig.isFetchNamesrvAddrByAddressServer()) { 166 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 167 168 @Override 169 public void run() { 170 try { 171 BrokerController.this.brokerOuterAPI.fetchNameServerAddr(); 172 } catch (Throwable e) { 173 log.error("ScheduledTask fetchNameServerAddr exception", e); 174 } 175 } 176 }, 1000 * 10, 1000 * 60 * 2, TimeUnit.MILLISECONDS); 177 } 178 179 if (!messageStoreConfig.isEnableDLegerCommitLog()) { 180 if (BrokerRole.SLAVE == this.messageStoreConfig.getBrokerRole()) { 181 if (this.messageStoreConfig.getHaMasterAddress() != null && this.messageStoreConfig.getHaMasterAddress().length() >= 6) { 182 this.messageStore.updateHaMasterAddress(this.messageStoreConfig.getHaMasterAddress()); 183 this.updateMasterHAServerAddrPeriodically = false; 184 } else { 185 this.updateMasterHAServerAddrPeriodically = true; 186 } 187 } else { 188 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 189 @Override 190 public void run() { 191 try { 192 BrokerController.this.printMasterAndSlaveDiff(); 193 } catch (Throwable e) { 194 log.error("schedule printMasterAndSlaveDiff error.", e); 195 } 196 } 197 }, 1000 * 10, 1000 * 60, TimeUnit.MILLISECONDS); 198 } 199 } 200 201 if (TlsSystemConfig.tlsMode != TlsMode.DISABLED) { 202 // Register a listener to reload SslContext 203 try { 204 fileWatchService = new FileWatchService( 205 new String[] { 206 TlsSystemConfig.tlsServerCertPath, 207 TlsSystemConfig.tlsServerKeyPath, 208 TlsSystemConfig.tlsServerTrustCertPath 209 }, 210 new FileWatchService.Listener() { 211 boolean certChanged, keyChanged = false; 212 213 @Override 214 public void onChanged(String path) { 215 if (path.equals(TlsSystemConfig.tlsServerTrustCertPath)) { 216 log.info("The trust certificate changed, reload the ssl context"); 217 reloadServerSslContext(); 218 } 219 if (path.equals(TlsSystemConfig.tlsServerCertPath)) { 220 certChanged = true; 221 } 222 if (path.equals(TlsSystemConfig.tlsServerKeyPath)) { 223 keyChanged = true; 224 } 225 if (certChanged && keyChanged) { 226 log.info("The certificate and private key changed, reload the ssl context"); 227 certChanged = keyChanged = false; 228 reloadServerSslContext(); 229 } 230 } 231 232 private void reloadServerSslContext() { 233 ((NettyRemotingServer) remotingServer).loadSslContext(); 234 ((NettyRemotingServer) fastRemotingServer).loadSslContext(); 235 } 236 }); 237 } catch (Exception e) { 238 log.warn("FileWatchService created error, can't load the certificate dynamically"); 239 } 240 } 241 initialTransaction(); 242 initialAcl(); 243 initialRpcHooks(); 244 } 245 return result; 246 }
首先完成对…/store/config/topics.json、…/store/config/consumerOffset.json、
…/store/config/subscriptionGroup.json、…/store/config/consumerFilter.json这几个文件的加载
接着创建一个DefaultMessageStore，这是Broker的核心存储
DefaultMessageStore的构造：
1 private final ConcurrentMap<String/* topic */, ConcurrentMap<Integer/* queueId */, ConsumeQueue>> consumeQueueTable; 2 ...... 3 public DefaultMessageStore(final MessageStoreConfig messageStoreConfig, final BrokerStatsManager brokerStatsManager, 4 final MessageArrivingListener messageArrivingListener, final BrokerConfig brokerConfig) throws IOException { 5 this.messageArrivingListener = messageArrivingListener; 6 this.brokerConfig = brokerConfig; 7 this.messageStoreConfig = messageStoreConfig; 8 this.brokerStatsManager = brokerStatsManager; 9 // 请求定位服务 10 this.allocateMappedFileService = new AllocateMappedFileService(this); 11 // 存储服务 12 if (messageStoreConfig.isEnableDLegerCommitLog()) { 13 this.commitLog = new DLedgerCommitLog(this); 14 } else { 15 this.commitLog = new CommitLog(this); 16 } 17 // 消费队列信息 18 this.consumeQueueTable = new ConcurrentHashMap<>(32); 19 // 刷新队列服务 20 this.flushConsumeQueueService = new FlushConsumeQueueService(); 21 // 清除CommitLog数据服务 22 this.cleanCommitLogService = new CleanCommitLogService(); 23 // 清除消费队列服务 24 this.cleanConsumeQueueService = new CleanConsumeQueueService(); 25 this.storeStatsService = new StoreStatsService(); 26 // 索引服务 27 this.indexService = new IndexService(this); 28 29 // HA服务，主从复制 30 if (!messageStoreConfig.isEnableDLegerCommitLog()) { 31 this.haService = new HAService(this); 32 } else { 33 this.haService = null; 34 } 35 this.reputMessageService = new ReputMessageService(); 36 this.scheduleMessageService = new ScheduleMessageService(this); 37 38 this.transientStorePool = new TransientStorePool(messageStoreConfig); 39 40 if (messageStoreConfig.isTransientStorePoolEnable()) { 41 this.transientStorePool.init(); 42 } 43 44 this.allocateMappedFileService.start(); 45 46 this.indexService.start(); 47 48 this.dispatcherList = new LinkedList<>(); 49 this.dispatcherList.addLast(new CommitLogDispatcherBuildConsumeQueue()); 50 this.dispatcherList.addLast(new CommitLogDispatcherBuildIndex()); 51 52 File file = new File(StorePathConfigHelper.getLockFile(messageStoreConfig.getStorePathRootDir())); 53 MappedFile.ensureDirOK(file.getParent()); 54 lockFile = new RandomAccessFile(file, "rw"); 55 }
可以看到DefaultMessageStore的构造会创建很多服务，来管理store的存储
其中isEnableDLegerCommitLog用来判断是否使用DLeger，默认false是关闭的
所以在默认情况下使用CommitLog + HAService
关于DLeger可参考这篇博客 【Dledger-RocketMQ 基于Raft协议的commitlog存储库】
后续的主从复制还是以CommitLog + HAService为主
回到initialize方法，接着会调用DefaultMessageStore的load方法：
1 public boolean load() { 2 boolean result = true; 3 4 try { 5 boolean lastExitOK = !this.isTempFileExist(); 6 log.info("last shutdown {}", lastExitOK ? "normally" : "abnormally"); 7 8 if (null != scheduleMessageService) { 9 result = result && this.scheduleMessageService.load(); 10 } 11 12 // load Commit Log 13 result = result && this.commitLog.load(); 14 15 // load Consume Queue 16 result = result && this.loadConsumeQueue(); 17 18 if (result) { 19 this.storeCheckpoint = 20 new StoreCheckpoint(StorePathConfigHelper.getStoreCheckpoint(this.messageStoreConfig.getStorePathRootDir())); 21 22 this.indexService.load(lastExitOK); 23 24 this.recover(lastExitOK); 25 26 log.info("load over, and the max phy offset = {}", this.getMaxPhyOffset()); 27 } 28 } catch (Exception e) { 29 log.error("load exception", e); 30 result = false; 31 } 32 33 if (!result) { 34 this.allocateMappedFileService.shutdown(); 35 } 36 37 return result; 38 }
这里会加载CommitLog和ConsumeQueue对应的文件
接着创建熟悉的NettyRemotingServer，在前面博客中介绍过了，就不再展开
这里会根据nettyServerConfig克隆一份服务端配置，以此创建fastRemotingServer服务端，只不过这个服务端侦听的是上面服务端端口减2的端口号
看过我前面的博客就会发现这个fastRemotingServer的端口号其实就是之前提到过的VIP通道
详见：
接着会根据不同的需求创建很多不同的线程池
然后调用registerProcessor方法：
registerProcessor方法：
1 public void registerProcessor() { 2 /** 3 * SendMessageProcessor 4 */ 5 SendMessageProcessor sendProcessor = new SendMessageProcessor(this); 6 sendProcessor.registerSendMessageHook(sendMessageHookList); 7 sendProcessor.registerConsumeMessageHook(consumeMessageHookList); 8 9 this.remotingServer.registerProcessor(RequestCode.SEND_MESSAGE, sendProcessor, this.sendMessageExecutor); 10 this.remotingServer.registerProcessor(RequestCode.SEND_MESSAGE_V2, sendProcessor, this.sendMessageExecutor); 11 this.remotingServer.registerProcessor(RequestCode.SEND_BATCH_MESSAGE, sendProcessor, this.sendMessageExecutor); 12 this.remotingServer.registerProcessor(RequestCode.CONSUMER_SEND_MSG_BACK, sendProcessor, this.sendMessageExecutor); 13 this.fastRemotingServer.registerProcessor(RequestCode.SEND_MESSAGE, sendProcessor, this.sendMessageExecutor); 14 this.fastRemotingServer.registerProcessor(RequestCode.SEND_MESSAGE_V2, sendProcessor, this.sendMessageExecutor); 15 this.fastRemotingServer.registerProcessor(RequestCode.SEND_BATCH_MESSAGE, sendProcessor, this.sendMessageExecutor); 16 this.fastRemotingServer.registerProcessor(RequestCode.CONSUMER_SEND_MSG_BACK, sendProcessor, this.sendMessageExecutor); 17 /** 18 * PullMessageProcessor 19 */ 20 this.remotingServer.registerProcessor(RequestCode.PULL_MESSAGE, this.pullMessageProcessor, this.pullMessageExecutor); 21 this.pullMessageProcessor.registerConsumeMessageHook(consumeMessageHookList); 22 23 /** 24 * QueryMessageProcessor 25 */ 26 NettyRequestProcessor queryProcessor = new QueryMessageProcessor(this); 27 this.remotingServer.registerProcessor(RequestCode.QUERY_MESSAGE, queryProcessor, this.queryMessageExecutor); 28 this.remotingServer.registerProcessor(RequestCode.VIEW_MESSAGE_BY_ID, queryProcessor, this.queryMessageExecutor); 29 30 this.fastRemotingServer.registerProcessor(RequestCode.QUERY_MESSAGE, queryProcessor, this.queryMessageExecutor); 31 this.fastRemotingServer.registerProcessor(RequestCode.VIEW_MESSAGE_BY_ID, queryProcessor, this.queryMessageExecutor); 32 33 /** 34 * ClientManageProcessor 35 */ 36 ClientManageProcessor clientProcessor = new ClientManageProcessor(this); 37 this.remotingServer.registerProcessor(RequestCode.HEART_BEAT, clientProcessor, this.heartbeatExecutor); 38 this.remotingServer.registerProcessor(RequestCode.UNREGISTER_CLIENT, clientProcessor, this.clientManageExecutor); 39 this.remotingServer.registerProcessor(RequestCode.CHECK_CLIENT_CONFIG, clientProcessor, this.clientManageExecutor); 40 41 this.fastRemotingServer.registerProcessor(RequestCode.HEART_BEAT, clientProcessor, this.heartbeatExecutor); 42 this.fastRemotingServer.registerProcessor(RequestCode.UNREGISTER_CLIENT, clientProcessor, this.clientManageExecutor); 43 this.fastRemotingServer.registerProcessor(RequestCode.CHECK_CLIENT_CONFIG, clientProcessor, this.clientManageExecutor); 44 45 /** 46 * ConsumerManageProcessor 47 */ 48 ConsumerManageProcessor consumerManageProcessor = new ConsumerManageProcessor(this); 49 this.remotingServer.registerProcessor(RequestCode.GET_CONSUMER_LIST_BY_GROUP, consumerManageProcessor, this.consumerManageExecutor); 50 this.remotingServer.registerProcessor(RequestCode.UPDATE_CONSUMER_OFFSET, consumerManageProcessor, this.consumerManageExecutor); 51 this.remotingServer.registerProcessor(RequestCode.QUERY_CONSUMER_OFFSET, consumerManageProcessor, this.consumerManageExecutor); 52 53 this.fastRemotingServer.registerProcessor(RequestCode.GET_CONSUMER_LIST_BY_GROUP, consumerManageProcessor, this.consumerManageExecutor); 54 this.fastRemotingServer.registerProcessor(RequestCode.UPDATE_CONSUMER_OFFSET, consumerManageProcessor, this.consumerManageExecutor); 55 this.fastRemotingServer.registerProcessor(RequestCode.QUERY_CONSUMER_OFFSET, consumerManageProcessor, this.consumerManageExecutor); 56 57 /** 58 * EndTransactionProcessor 59 */ 60 this.remotingServer.registerProcessor(RequestCode.END_TRANSACTION, new EndTransactionProcessor(this), this.endTransactionExecutor); 61 this.fastRemotingServer.registerProcessor(RequestCode.END_TRANSACTION, new EndTransactionProcessor(this), this.endTransactionExecutor); 62 63 /** 64 * Default 65 */ 66 AdminBrokerProcessor adminProcessor = new AdminBrokerProcessor(this); 67 this.remotingServer.registerDefaultProcessor(adminProcessor, this.adminBrokerExecutor); 68 this.fastRemotingServer.registerDefaultProcessor(adminProcessor, this.adminBrokerExecutor); 69 }
这里会创建好几种Processor，通过registerProcessor方法同时注册到remotingServer和fastRemotingServer中
registerProcessor方法：
1 public void registerProcessor(int requestCode, NettyRequestProcessor processor, ExecutorService executor) { 2 ExecutorService executorThis = executor; 3 if (null == executor) { 4 executorThis = this.publicExecutor; 5 } 6 7 Pair<NettyRequestProcessor, ExecutorService> pair = new Pair<NettyRequestProcessor, ExecutorService>(processor, executorThis); 8 this.processorTable.put(requestCode, pair); 9 }
这里实际上就是向processorTable进行了记录的添加，为的是后续收到请求能做出对应的处理
processorTable：
1 protected final HashMap<Integer/* request code */, Pair<NettyRequestProcessor, ExecutorService>> processorTable = 2 new HashMap<Integer, Pair<NettyRequestProcessor, ExecutorService>>(64);
这里的SendMessageProcessor很重要，后续会详细介绍
在完成registerProcessor后，会创建8个定时任务
①
1 BrokerController.this.getBrokerStats().record();
定时打印Broker的状态
②
1 BrokerController.this.consumerOffsetManager.persist();
定时向consumerOffset.json文件中写入消费者偏移量
③
1 BrokerController.this.consumerFilterManager.persist();
定时向consumerFilter.json文件写入消费者过滤器信息
④
1 BrokerController.this.protectBroker();
定时禁用消费慢的consumer，保护Broker，需要设置disableConsumeIfConsumerReadSlowly属性，默认false
⑤
1 BrokerController.this.printWaterMark();
定时打印Send、Pull、Query、Transaction队列信息
⑥
1 public void run() { 2 try { 3 log.info("dispatch behind commit log {} bytes", BrokerController.this.getMessageStore().dispatchBehindBytes()); 4 } catch (Throwable e) { 5 log.error("schedule dispatchBehindBytes error.", e); 6 } 7 }
定时打印已存储在提交日志中但尚未调度到消费队列的字节数
⑦
1 if (this.brokerConfig.getNamesrvAddr() != null) { 2 this.brokerOuterAPI.updateNameServerAddressList(this.brokerConfig.getNamesrvAddr()); 3 log.info("Set user specified name server address: {}", this.brokerConfig.getNamesrvAddr()); 4 } else if (this.brokerConfig.isFetchNamesrvAddrByAddressServer()) { 5 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 6 7 @Override 8 public void run() { 9 try { 10 BrokerController.this.brokerOuterAPI.fetchNameServerAddr(); 11 } catch (Throwable e) { 12 log.error("ScheduledTask fetchNameServerAddr exception", e); 13 } 14 } 15 }, 1000 * 10, 1000 * 60 * 2, TimeUnit.MILLISECONDS); 16 }
若是设置了NamesrvAddr，需要通过updateNameServerAddressList完成一次NameServer地址的跟新（updateNameServerAddressList在前面博客介绍过了）
若是设置了NamesrvAddr，并且设置了fetchNamesrvAddrByAddressServer属性（默认关闭），需要定时获取更新NameServer地址（fetchNameServerAddr方法在之前博客也介绍过）
⑧
1 if (!messageStoreConfig.isEnableDLegerCommitLog()) { 2 if (BrokerRole.SLAVE == this.messageStoreConfig.getBrokerRole()) { 3 if (this.messageStoreConfig.getHaMasterAddress() != null && this.messageStoreConfig.getHaMasterAddress().length() >= 6) { 4 this.messageStore.updateHaMasterAddress(this.messageStoreConfig.getHaMasterAddress()); 5 this.updateMasterHAServerAddrPeriodically = false; 6 } else { 7 this.updateMasterHAServerAddrPeriodically = true; 8 } 9 } else { 10 this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() { 11 @Override 12 public void run() { 13 try { 14 BrokerController.this.printMasterAndSlaveDiff(); 15 } catch (Throwable e) { 16 log.error("schedule printMasterAndSlaveDiff error.", e); 17 } 18 } 19 }, 1000 * 10, 1000 * 60, TimeUnit.MILLISECONDS); 20 } 21 }
在非DLeger模式下
若是SLAVE，则需要检查是否设置了HA的Master地址
若设置了Master地址要通过updateHaMasterAddress方法向更新Master地址
updateHaMasterAddress方法实则是在HAClient中实现的：
1 public void updateMasterAddress(final String newAddr) { 2 String currentAddr = this.masterAddress.get(); 3 if (currentAddr == null || !currentAddr.equals(newAddr)) { 4 this.masterAddress.set(newAddr); 5 log.info("update master address, OLD: " + currentAddr + " NEW: " + newAddr); 6 } 7 }
非常简单，只是一个比较替换的操作
若没有设置需要更改updateMasterHAServerAddrPeriodically为true，在后面会有用
若是MASTER，则需要定时打印slave落后的字节数
设置完定时任务后，和NameServer中一样设置了对SslContext的监听
接着通过initialTransaction方法，加载事务需要的实例
initialTransaction方法：
1 private void initialTransaction() { 2 this.transactionalMessageService = ServiceProvider.loadClass(ServiceProvider.TRANSACTION_SERVICE_ID, TransactionalMessageService.class); 3 if (null == this.transactionalMessageService) { 4 this.transactionalMessageService = new TransactionalMessageServiceImpl(new TransactionalMessageBridge(this, this.getMessageStore())); 5 log.warn("Load default transaction message hook service: {}", TransactionalMessageServiceImpl.class.getSimpleName()); 6 } 7 this.transactionalMessageCheckListener = ServiceProvider.loadClass(ServiceProvider.TRANSACTION_LISTENER_ID, AbstractTransactionalMessageCheckListener.class); 8 if (null == this.transactionalMessageCheckListener) { 9 this.transactionalMessageCheckListener = new DefaultTransactionalMessageCheckListener(); 10 log.warn("Load default discard message hook service: {}", DefaultTransactionalMessageCheckListener.class.getSimpleName()); 11 } 12 this.transactionalMessageCheckListener.setBrokerController(this); 13 this.transactionalMessageCheckService = new TransactionalMessageCheckService(this); 14 }
这里动态加载了TransactionalMessageService和AbstractTransactionalMessageCheckListener的实现类，位于如下
“META-INF/service/org.apache.rocketmq.broker.transaction.TransactionalMessageService”
“META-INF/service/org.apache.rocketmq.broker.transaction.AbstractTransactionalMessageCheckListener”
还创建了TransactionalMessageCheckService
initialAcl会创建ACL权限检查：
1 private void initialAcl() { 2 if (!this.brokerConfig.isAclEnable()) { 3 log.info("The broker dose not enable acl"); 4 return; 5 } 6 7 List<AccessValidator> accessValidators = ServiceProvider.load(ServiceProvider.ACL_VALIDATOR_ID, AccessValidator.class); 8 if (accessValidators == null || accessValidators.isEmpty()) { 9 log.info("The broker dose not load the AccessValidator"); 10 return; 11 } 12 13 for (AccessValidator accessValidator: accessValidators) { 14 final AccessValidator validator = accessValidator; 15 this.registerServerRPCHook(new RPCHook() { 16 17 @Override 18 public void doBeforeRequest(String remoteAddr, RemotingCommand request) { 19 //Do not catch the exception 20 validator.validate(validator.parse(request, remoteAddr)); 21 } 22 23 @Override 24 public void doAfterResponse(String remoteAddr, RemotingCommand request, RemotingCommand response) { 25 } 26 }); 27 } 28 }
需要设置aclEnable属性，默认关闭
若是设置了，同样会加载”META-INF/service/org.apache.rocketmq.acl.AccessValidator”配置的AccessValidator实体类
然后将其包装成RPC钩子，注册到remotingServer和fastRemotingServer中，用于请求的调用validate方法进行ACL权限检查
initialRpcHooks方法则会注册配置了的RPC钩子：
1 private void initialRpcHooks() { 2 List<RPCHook> rpcHooks = ServiceProvider.load(ServiceProvider.RPC_HOOK_ID, RPCHook.class); 3 if (rpcHooks == null || rpcHooks.isEmpty()) { 4 return; 5 } 6 for (RPCHook rpcHook: rpcHooks) { 7 this.registerServerRPCHook(rpcHook); 8 } 9 }
加载”META-INF/service/org.apache.rocketmq.remoting.RPCHook”下的配置的实体类
到此Broker启动前的准备工作已经完成，后面start方法会进行真正的启动，在下一篇博客继续分析
