ManagedChannel channel = ManagedChannelBuilder.forAddress(host, port) .usePlaintext() .build(); HelloServiceGrpc.HelloServiceBlockingStub stub = HelloServiceGrpc.newBlockingStub(channel); HelloResponse response = stub.sayHello(HelloRequest.newBuilder() .setName("John") .build()); channel.shutdown(); ChannelPool pool = ChannelPoolBuilder.newBuilder() .maxTotal(10) .idleTimeout(Duration.ofMinutes(5)) .build(); ManagedChannel channel = pool.borrowChannel(host, port); pool.returnChannel(channel); pool.close(); StreamServiceGrpc.StreamServiceStub stub = StreamServiceGrpc.newStub(channel); StreamObserver<Request> requestObserver = stub.myMethod(new StreamObserver<Response>() { @Override public void onNext(Response response) { System.out.println("Received response: " + response); } @Override public void onError(Throwable t) { System.err.println("Error: " + t.getMessage()); } @Override public void onCompleted() { System.out.println("Completed"); } }); for (int i = 0; i < 10; i++) { requestObserver.onNext(Request.newBuilder() .setData("Data " + i) .build()); } requestObserver.onCompleted(); ServerBuilder.forPort(port) .maxInboundMessageSize(10 * 1024 * 1024) // 10MB .build(); ManagedChannelBuilder.forAddress(host, port) .maxInboundMessageSize(10 * 1024 * 1024) // 10MB .build();