Error in SQL Server to WCF development - sql-server

Question

I am testing a DB that have two tables (Satellite and Channel) to be exposed as I need using WCF. fortunately, I tried everything I know and online for more that I week now and I can't solve the problem.
This is the service contract IService.cs
[ServiceContract]
public interface IService
{
[OperationContract]
List<Satalite> SelectSatalite(int satNum);
[OperationContract]
List<Satalite> SataliteList();
[OperationContract]
List<Channel> ChannelList(int satNum);
[OperationContract]
String Sat(int satNum);
}
And this is the Service.svc.cs file
public class Service : IService
{
DataDbDataContext DbObj = new DataDbDataContext();
public List<Satalite> SataliteList()
{
var satList = from r in DbObj.Satalites
select r;
return satList.ToList();
}
public List<Satalite> SelectSatalite(int satNum)
{
var satList = from r in DbObj.Satalites
where r.SateliteID == satNum
select r;
return satList.ToList();
}
public List<Channel> ChannelList(int satNum)
{
var channels = from r in DbObj.Channels
where r.SateliteID == satNum
select r;
return channels.ToList();
}
public String Sat(int satNum)
{
Satalite satObj = new Satalite();
satObj = DbObj.Satalites.Single(p => p.SateliteID == satNum);
return satObj.Name;
}
}
Whenever I try to run the first three I got an error when testing them using wcftestclient.exe, the last one works with no issues.
The underlying connection was closed: The connection was closed
unexpectedly.
Server stack trace:
at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException
webException, HttpWebRequest request, HttpAbortReason abortReason)
at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan
timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message,
TimeSpan timeout)
at System.ServiceModel.Dispatcher.RequestChannelBinder.Request(Message
message, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannel.Call(String action,
Boolean oneway, ProxyOperationRuntime operation, Object[] ins,
Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage
methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage
message)
Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage
reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&
msgData, Int32 type) at IService.SelectSatalite(Int32 satNum)
at ServiceClient.SelectSatalite(Int32 satNum)
Inner Exception: The underlying connection was closed: The connection
was closed unexpectedly.
at System.Net.HttpWebRequest.GetResponse()
at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan
timeout)
What I understand is that the error happens for the custom classes which are the DB tables, if I used a known type by the .net compiler (ex. int or string) it will work with no problems. Fortunately, I didn't find a solution.

Answer 1

The error appears to be one of two reasons:
a timeout since you're returning too much data, e.g. the selection of the data from the database takes too long for the service method to complete in time
or:
the message size is too large, because you're selecting too much data, and thus the WCF communication aborts before the whole data has been returned
My solution:
don't select all data from the tables! Return only as much data as you can really handle / display, e.g. 10 rows, 20 rows or a maximum of 100 rows....
Try this - if you change your method to:
public List<Satalite> SataliteList(int count)
{
var satList = (from r in DbObj.Satalites
select r).Take(count);
return satList.ToList();
}
Can you call this from the WCF Test Client with e.g. count = 10 or count = 50 ??

Answer 2

Adjusting timeout settings on server and client side will help you.
Server Side adjust the SendTimeout attribute of binding element and on client side adjust the RecieveTimeout attribute of binding element.
Thanks,