如何理解RocketMQ存储中的主从同步

@1 BrokerStartup#mainstart(createBrokerController(args));@2 BrokerStartup#createBrokerControllerboolean initResult = controller.initialize();@3 BrokerController#initializethis.messageStore = new DefaultMessageStore@4 DefaultMessageStore#DefaultMessageStore()this.haService = new HAService(this);this.defaultMessageStore = defaultMessageStore;this.acceptSocketService =new AcceptSocketService(defaultMessageStore.getMessageStoreConfig().getHaListenPort());this.groupTransferService = new GroupTransferService();this.haClient = new HAClient();

@1 BrokerStartup#startcontroller.start();@2 BrokerController#startthis.messageStore.start();@3 DefaultMessageStore#start@4 this.haService.start();this.acceptSocketService.beginAccept();this.acceptSocketService.start();this.groupTransferService.start();this.haClient.start();

//构造方法public HAConnection(final HAService haService, final SocketChannel socketChannel) throws IOException {this.haService = haService;this.socketChannel = socketChannel;//获取客户端请求地址this.clientAddr = this.socketChannel.socket().getRemoteSocketAddress().toString();//将通道调整为非阻塞this.socketChannel.configureBlocking(false);//关闭连接前将数据发送完毕this.socketChannel.socket().setSoLinger(false, -1);//将Nagle算法关闭，客户端每发送一次数据无论大小，都会将其发送出去this.socketChannel.socket().setTcpNoDelay(true);//设置接受缓存区为64Kthis.socketChannel.socket().setReceiveBufferSize(1024 * 64);//设置发包缓存区为64Kthis.socketChannel.socket().setSendBufferSize(1024 * 64);//写数据线程类this.writeSocketService = new WriteSocketService(this.socketChannel);//读数据线程类this.readSocketService = new ReadSocketService(this.socketChannel);this.haService.getConnectionCount().incrementAndGet();}//启动public void start() {//启动读数据线程this.readSocketService.start();//启动写数据线程this.writeSocketService.start();}