Client's method description for WCF service - wcf

Question

I have a WCF service (hosted in windows-service) and a client for it.
They interact as follows: client sends a request, service gets it and returns HTTP 200. Also client passes its address for the answer in the WS-Addressing header. For the moment that's all
After a few hours windows-service should send a result for that request. Client has a web-method that will get the result. So the question is: where should be a description (name of the method, its parameters) for the client's method that will get the result? Should the client expose its WSDL, or should I put that description in my WSDL (if it works that way)?

Answer 1

As I understand your scenario, you have two services, let's call them Service A (hosted in a Windows Service) and Service B. Service B sends a request to Service A (in other words, it's acting like a client) to have Service A start a long-running task of some sort.
When the task is complete, Service A needs to send the results to Service B. Since it's a long-running task, using a duplex binding would not be ideal. However, Service A could call a method exposed by Service B to send the results.
Something like this:
[ServiceContract]
public interface IServiceA
{
[OperationContract]
public void StartWork();
}
[ServiceContract]
public interface IServiceB
{
[OperationContract]
public void ReceiveResults(ResultData data);
}
where ResultData is some object containing the results (could be a simple type as well, this is simply for illustration). ServiceA's StartWork can return void (the response will still be sent to the client, since it's not marked as IsOneWay=true). Semi-pseduo code follows:
Start the task:
ServiceAClient client = new ServiceAClient();
client.Open();
client.StartWork();
client.Close();
Service A sends the results to Service B when the task is complete:
ResultData results = new ResultData();
ServiceBClient client = new ServiceBClient();
client.Open();
client.ReceiveResults(results);
client.Close();
In this case, the method to receive the results will be part of Service B's WSDL, as Service A will call that method.