sofa-rpc源码解析-服务端netty启动过程

  1. 创建server
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    //ServerConfig.java

    public synchronized Server buildIfAbsent() {
            if (server != null) {
                return server;
            }
            // 提前检查协议+序列化方式
            // ConfigValueHelper.check(ProtocolType.valueOf(getProtocol()),
            //                SerializationType.valueOf(getSerialization()));

            server = ServerFactory.getServer(this);
            return server;
        }

如果不存在则创建,关键在于ServerFactory的getServer方法

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    /**
     * 全部服务端
     */
    private final static ConcurrentHashMap<String, Server> SERVER_MAP = new ConcurrentHashMap<String, Server>();
    
public synchronized static Server getServer(ServerConfig serverConfig) {
        try {
            Server server = SERVER_MAP.get(Integer.toString(serverConfig.getPort()));
            if (server == null) {
                // 算下网卡和端口
                resolveServerConfig(serverConfig);

                ExtensionClass<Server> ext = ExtensionLoaderFactory.getExtensionLoader(Server.class)
                    .getExtensionClass(serverConfig.getProtocol());
                if (ext == null) {
                    throw ExceptionUtils.buildRuntime("server.protocol", serverConfig.getProtocol(),
                        "Unsupported protocol of server!");
                }
                server = ext.getExtInstance();
                server.init(serverConfig);
                SERVER_MAP.put(serverConfig.getPort() + "", server);
            }
            return server;
        } catch (SofaRpcRuntimeException e) {
            throw e;
        } catch (Throwable e) {
            throw new SofaRpcRuntimeException(e.getMessage(), e);
        }
    }

getServer默认返回的是一个BoltServer

2.启动server

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DefaultProviderBootstrap.java
for (ServerConfig serverConfig : serverConfigs) {
                try {
                    Server server = serverConfig.buildIfAbsent();
                    // 注册序列化接口
                    server.registerProcessor(providerConfig, providerProxyInvoker);
                    if (serverConfig.isAutoStart()) {
                        server.start();
                    }
                } catch (SofaRpcRuntimeException e) {
                    throw e;
                } catch (Exception e) {
                    LOGGER.errorWithApp(appName, "Catch exception when register processor to server: "
                        + serverConfig.getId(), e);
                }
            }
            

//BoltServer.java            
@Override
public void start() {
        if (started) {
            return;
        }
        synchronized (this) {
            if (started) {
                return;
            }
            // 生成Server对象
            remotingServer = initRemotingServer();
            try {
                if (remotingServer.start(serverConfig.getBoundHost())) {
                    if (LOGGER.isInfoEnabled()) {
                        LOGGER.info("Bolt server has been bind to {}:{}", serverConfig.getBoundHost(),
                            serverConfig.getPort());
                    }
                } else {
                    throw new SofaRpcRuntimeException("Failed to start bolt server, see more detail from bolt log.");
                }
                started = true;

                if (EventBus.isEnable(ServerStartedEvent.class)) {
                    EventBus.post(new ServerStartedEvent(serverConfig, bizThreadPool));
                }

            } catch (SofaRpcRuntimeException e) {
                throw e;
            } catch (Exception e) {
                throw new SofaRpcRuntimeException("Failed to start bolt server!", e);
            }
        }
    }
    
protected RemotingServer initRemotingServer() {
        // 绑定到端口
        RemotingServer remotingServer = new RpcServer(serverConfig.getPort());
        remotingServer.registerUserProcessor(boltServerProcessor);
        return remotingServer;
}
  • 启动过程使用了双重检查机制，防止Server重复启动

  • initRemotingServer方法里初始化了netty的一些配置，跟到代码里可以看到我们通常启动一个netty服务端需要的bossGroup(workerGroup在初始化过程里doInit方法里设置好)

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    //RpcServer.java ->sofa-bolt项目
    private static final NioEventLoopGroup workerGroup = new NioEventLoopGroup(Runtime.getRuntime().availableProcessors() * 2, new NamedThreadFactory("Rpc-netty-server-worker"));

        public RpcServer(int port) {
            super(port);
            this.globalSwitch = new GlobalSwitch();
            this.connectionEventListener = new ConnectionEventListener();
            this.userProcessors = new ConcurrentHashMap(4);
            this.bossGroup = new NioEventLoopGroup(1, new NamedThreadFactory("Rpc-netty-server-boss"));
        }

  • 启动:

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    protected boolean doStart(String ip) throws InterruptedException {
        this.channelFuture = this.bootstrap.bind(new InetSocketAddress(ip, this.port)).sync();
        return this.channelFuture.isSuccess();
    }

标准的netty服务端启动模板代码