Nacos源码—9.Nacos升级gRPC分析八

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于 2025-05-13 23:58:21 发布 · 1k 阅读

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#Nacos #配置中心 #注册中心

大纲

10.gRPC客户端初始化分析

11.gRPC客户端的心跳机制(健康检查)

12.gRPC服务端如何处理客户端的建立连接请求

13.gRPC服务端如何映射各种请求与对应的Handler处理类

14.gRPC简单介绍

12.gRPC服务端如何处理客户端的建立连接请求

(1)gRPC服务端是如何启动的

(2)connectionId如何绑定Client对象的

(1)gRPC服务端是如何启动的

BaseRpcServer类有一个被@PostConstruct修饰的start()方法，该方法会调用BaseGrpcServer的startServer()方法来启动gRPC服务端。

在BaseGrpcServer的startServer()方法中，首先会调用BaseGrpcServer的addServices()方法添加服务，然后会使用建造者模式通过ServerBuilder创建gRPC框架的Server对象，最后启动gRPC框架的Server服务端，即启动一个NettyServer服务端。

//abstract rpc server.
public abstract class BaseRpcServer {
    ...
    //Start sever. 启动gRPC服务端
    @PostConstruct
    public void start() throws Exception {
        String serverName = getClass().getSimpleName();
        Loggers.REMOTE.info("Nacos {} Rpc server starting at port {}", serverName, getServicePort());

        //调用BaseGrpcServer.startServer()方法启动gRPC服务端
        startServer();

        Loggers.REMOTE.info("Nacos {} Rpc server started at port {}", serverName, getServicePort());
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            Loggers.REMOTE.info("Nacos {} Rpc server stopping", serverName);
            try {
                BaseRpcServer.this.stopServer();
                Loggers.REMOTE.info("Nacos {} Rpc server stopped successfully...", serverName);
            } catch (Exception e) {
                Loggers.REMOTE.error("Nacos {} Rpc server stopped fail...", serverName, e);
            }
        }));
    }
    
    //get service port.
    public int getServicePort() {
        return EnvUtil.getPort() + rpcPortOffset();
    }
    ...
}

//Grpc implementation as a rpc server.
public abstract class BaseGrpcServer extends BaseRpcServer {
    ...
    @Override
    public void startServer() throws Exception {
        final MutableHandlerRegistry handlerRegistry = new MutableHandlerRegistry();
    
        //server interceptor to set connection id. 定义请求拦截器
        ServerInterceptor serverInterceptor = new ServerInterceptor() {
            @Override
            public <T, S> ServerCall.Listener<T> interceptCall(ServerCall<T, S> call, Metadata headers, ServerCallHandler<T, S> next) {
                Context ctx = Context.current()
                    .withValue(CONTEXT_KEY_CONN_ID, call.getAttributes().get(TRANS_KEY_CONN_ID))
                    .withValue(CONTEXT_KEY_CONN_REMOTE_IP, call.getAttributes().get(TRANS_KEY_REMOTE_IP))
                    .withValue(CONTEXT_KEY_CONN_REMOTE_PORT, call.getAttributes().get(TRANS_KEY_REMOTE_PORT))
                    .withValue(CONTEXT_KEY_CONN_LOCAL_PORT, call.getAttributes().get(TRANS_KEY_LOCAL_PORT));
                if (REQUEST_BI_STREAM_SERVICE_NAME.equals(call.getMethodDescriptor().getServiceName())) {
                    Channel internalChannel = getInternalChannel(call);
                    ctx = ctx.withValue(CONTEXT_KEY_CHANNEL, internalChannel);
                }
                return Contexts.interceptCall(ctx, call, headers, next);
            }
        };

        //1.调用BaseGrpcServer.addServices()方法添加服务
        addServices(handlerRegistry, serverInterceptor);

        //2.创建一个gRPC框架的Server对象，使用了建造者模式
        server = ServerBuilder.forPort(getServicePort()).executor(getRpcExecutor())
        .maxInboundMessageSize(getInboundMessageSize()).fallbackHandlerRegistry(handlerRegistry)
        .compressorRegistry(CompressorRegistry.getDefaultInstance())
        .decompressorRegistry(DecompressorRegistry.getDefaultInstance())
        .addTransportFilter(new ServerTransportFilter() {
            @Override
            public Attributes transportReady(Attributes transportAttrs) {
                InetSocketAddress remoteAddress = (InetSocketAddress) transportAttrs.get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
                InetSocketAddress localAddress = (InetSocketAddress) transportAttrs.get(Grpc.TRANSPORT_ATTR_LOCAL_ADDR);
                int remotePort = remoteAddress.getPort();
                int localPort = localAddress.getPort();
                String remoteIp = remoteAddress.getAddress().getHostAddress();
                Attributes attrWrapper = transportAttrs.toBuilder()
                    .set(TRANS_KEY_CONN_ID, System.currentTimeMill