nacos2.0.0 源码初识二 grpc服务端启动流程

grpc服务器启动源码流程图

grpc服务启动源码

1.1 GrpcSdkServer

nacos-core项目中，GrpcSdkServer 类上有@Service注解，所以项目启动时候会初始化此类实例

@Service
public class GrpcSdkServer extends BaseGrpcServer {
    
    private static final int PORT_OFFSET = 1000;
    
    @Override
    public int rpcPortOffset() {
        return PORT_OFFSET;
    }
    
    @Override
    public ThreadPoolExecutor getRpcExecutor() {
        return GlobalExecutor.sdkRpcExecutor;
    }
}

1.1.1 GrpcSdkServer 类继承关系

1.2 BaseRpcServer

父类中存在@PostConstruct，初始化后会调用此方法

@PostConstruct
public void start() throws Exception {
    ...
    startServer();
    ...
}

1.3 开启grpc服务

1.3.1 startServer

这个方法会构建io.grpc.Server，并启动服务，绑定为：nacos端口+1000

@Override
public void startServer() throws Exception {
    final MutableHandlerRegistry handlerRegistry = new MutableHandlerRegistry();
    // 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);
            }
            System.out.println("intercept："+call.getMethodDescriptor().getServiceName());
            return Contexts.interceptCall(ctx, call, headers, next);
        }
    };
	//grpc中添加处理服务
    addServices(handlerRegistry, serverInterceptor);
	//构造grpc服务端
    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.currentTimeMillis() + "_" + remoteIp + "_" + remotePort)
                            .set(TRANS_KEY_REMOTE_IP, remoteIp).set(TRANS_KEY_REMOTE_PORT, remotePort)
                            .set(TRANS_KEY_LOCAL_PORT, localPort).build();
                    String connectionId = attrWrapper.get(TRANS_KEY_CONN_ID);
                    Loggers.REMOTE_DIGEST.info("Connection transportReady,connectionId = {} ", connectionId);
                    return attrWrapper;

                }

                @Override
                public void transportTerminated(Attributes transportAttrs) {
                    String connectionId = null;
                    try {
                        connectionId = transportAttrs.get(TRANS_KEY_CONN_ID);
                    } catch (Exception e) {
                        // Ignore
                    }
                    if (StringUtils.isNotBlank(connectionId)) {
                        Loggers.REMOTE_DIGEST
                                .info("Connection transportTerminated,connectionId = {} ", connectionId);
                        connectionManager.unregister(connectionId);
                    }
                }
            }).build();
	//启动grpc
    server.start();
}

1.3.2 addServices方法

这里会向io.grpc.Server对象中注册服务，当有客户端连接或接收到请求时，会触发对应的服务

private void addServices(MutableHandlerRegistry handlerRegistry, ServerInterceptor... serverInterceptor) {
    final MethodDescriptor<Payload, Payload> unaryPayloadMethod = MethodDescriptor.<Payload, Payload>newBuilder()
            .setType(MethodDescriptor.MethodType.UNARY)
            .setFullMethodName(MethodDescriptor.generateFullMethodName(REQUEST_SERVICE_NAME, REQUEST_METHOD_NAME))
            .setRequestMarshaller(ProtoUtils.marshaller(Payload.getDefaultInstance()))
            .setResponseMarshaller(ProtoUtils.marshaller(Payload.getDefaultInstance())).build();
	//服务回调（客户端注册时，这里方法会接收到）
    final ServerCallHandler<Payload, Payload> payloadHandler = ServerCalls
            .asyncUnaryCall((request, responseObserver) -> {
            	//接收到数据，会回调此方法
                grpcCommonRequestAcceptor.request(request, responseObserver);
            });
	//构造服务
    final ServerServiceDefinition serviceDefOfUnaryPayload = ServerServiceDefinition.builder(REQUEST_SERVICE_NAME)
            .addMethod(unaryPayloadMethod, payloadHandler).build();
    //服务注册到grpc中
    handlerRegistry.addService(ServerInterceptors.intercept(serviceDefOfUnaryPayload, serverInterceptor));
	//构造服务
    final ServerCallHandler<Payload, Payload> biStreamHandler = ServerCalls.asyncBidiStreamingCall(
            (responseObserver) -> grpcBiStreamRequestAcceptor.requestBiStream(responseObserver));

    final MethodDescriptor<Payload, Payload> biStreamMethod = MethodDescriptor.<Payload, Payload>newBuilder()
            .setType(MethodDescriptor.MethodType.BIDI_STREAMING).setFullMethodName(MethodDescriptor
                    .generateFullMethodName(REQUEST_BI_STREAM_SERVICE_NAME, REQUEST_BI_STREAM_METHOD_NAME))
            .setRequestMarshaller(ProtoUtils.marshaller(Payload.newBuilder().build()))
            .setResponseMarshaller(ProtoUtils.marshaller(Payload.getDefaultInstance())).build();

    final ServerServiceDefinition serviceDefOfBiStream = ServerServiceDefinition
            .builder(REQUEST_BI_STREAM_SERVICE_NAME).addMethod(biStreamMethod, biStreamHandler).build();
    handlerRegistry.addService(ServerInterceptors.intercept(serviceDefOfBiStream, serverInterceptor));

}