WCF: How to handle errors when calling another WCF service? - wcf

Question

I have a project where I should write WCF service that calls another WCF service. It looks as following:
[ServiceContract]
public interface IAsurService
{
[OperationContract(ReplyAction = AsurService.ReplyAction_GetCatalogList)]
Message GetCatalogList();
public Message GetCatalogList()
{
// The external client service
GetNsiClient client = new GetNsiClient();
authContext auth = new authContext
{
company = "asur_nsi",
password = "lapshovva",
user = "dogm_LapshovVA"
};
catalogs catalogs = client.getCatalogList(auth);
How can I handle errors in this case? Can I use standard fault contract approach like this:
[DataContract]
public class AsurDataFaultException
{
private string reason;
[DataMember]
public string Reason
{
get { return reason; }
set { reason = value; }
}
}
public Message GetCatalogList()
{
// The external client service
GetNsiClient client = new GetNsiClient();
authContext auth = new authContext
{
company = "asur_nsi",
password = "lapshovva",
user = "dogm_LapshovVA"
};
catalogs catalogs = null;
try
{
catalogs = client.getCatalogList(auth);
}
catch (Exception exception)
{
AsurDataFaultException fault = new AsurDataFaultException();
fault.Reason = "The error: " + exception.Message.ToString();
throw new FaultException<AsurDataFaultException>(fault);
}
Or something else?
Thank you in advance.
Goran

Answer 1

If the remote WCF service's failure causes a failure of your code, then obviously you should throw a fault but that fault should not expose the inner details of the remote WCF service or its exception, like so:
catch (Exception exception)
{
// Indicate all that you may expose -- that the data is unavailable.
DataUnavailableFault fault = new DataUnavailableFault();
throw new FaultException<DataUnavailableFault>(fault);
}
You may of course also use a retry mechanism, but obviously if what you end up with is a failure in the remote service, you should indicate that to your caller by throwing an appropriate fault.