NoHttpResponseException with request forwarding

[lxp1250]

I am using 5.11.1 version and observed the same issue. I would like to know why this happens and what could be the fix.

` public class MockServerExample {

/* Set up service endpoint */
public static String HOST = "127.0.0.1";
public static int PORT = 1080;

public static void start() {
        startClientAndServer(PORT);
        createExpectations();
}

private static void createExpectation() {

        new MockServerClient(HOST, PORT)
                .when(
                        request()
                                .withPath("/path1/ping")
                )
                .forward(
                        forward()
                                .withHost("127.0.0.1")
                                .withPort(9000)
                );

        new MockServerClient(HOST, PORT)
                .when(
                        request()
                                .withPath("/path2")
                )
                .forward(
                        forwardOverriddenRequest(
                                request()
                                        .withPath("/path2")
                                        .withSocketAddress("127.0.0.1", 60000, SocketAddress.Scheme.HTTP)
                        )
                );`

It is basically testing request forwarding. Upon receiving the request, it forwards to localhost:60000 with same path. In the @beforeClass, it calls start().

The error I got is: DEBUG 19:36:31.880 [main] o.a.http.impl.execchain.RetryExec: The target server failed to respond ! org.apache.http.NoHttpResponseException: The target server failed to respond ! at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141) ~[httpclient-4.5.9.jar:4.5.9] ! at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56) ~[httpclient-4.5.9.jar:4.5.9] ! at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259) ~[httpcore-4.4.11.jar:4.4.11] ...

[lxp1250]

I verified if I change the forward to response, mocked server is able to return response successfully.

[jamesdbloom]

It looks like the problem is that there is nothing listening on 127.0.0.1:6000.