WCF Error while receiving the HTTP response to my service

Question

Hi guys I created a service using WCF but when I test my services some completed successfully why some is giving me the error below. Any Idea on how to solve these ? Thanks

An error occurred while receiving the HTTP response to http://localhost:8733/PortOperation/Operator_Service/ws. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.

Server stack trace: 
at System.ServiceModel.Channels.HttpChannelUtilities.ProcessGetResponseWebException(WebException webException, HttpWebRequest request, HttpAbortReason abortReason)
at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)
at System.ServiceModel.Channels.RequestChannel.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.RequestClientReliableChannelBinder`1.OnRequest(TRequestChannel channel, Message message, TimeSpan timeout, MaskingMode maskingMode)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout, MaskingMode maskingMode)
at System.ServiceModel.Channels.ClientReliableChannelBinder`1.Request(Message message, TimeSpan timeout)
at System.ServiceModel.Security.SecuritySessionClientSettings`1.SecurityRequestSessionChannel.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 IOperator_Service.GetAllUser(String ConnectionString)
at Operator_ServiceClient.GetAllUser(String ConnectionString)

Inner Exception:
The underlying connection was closed: An unexpected error occurred on a receive.
at System.Net.HttpWebRequest.GetResponse()
at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout)

Inner Exception:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.Connection.SyncRead(HttpWebRequest request, Boolean userRetrievedStream, Boolean probeRead)

Inner Exception:
An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

Answer 1

There are many scenarios when this type of error occurs.

First

Check that have you provided proper [DataContract] and [DataMember]? if this is not provided then this type of error occurs. You have to write [DataContract] above the class which you pass in response, and write [DataMember] above the class member which goes into the client response.

eg.

[DataContract]
class Program
{
  [DataMember] 
  public string Example{get;set}
}

Second

Check in the response if some minvalue of Data type is passed. That means some time data member is not initialized at that time it takes the minvalue. e.g. minValue of int is '-2147483648' so at some time it cannot be serialized and throws an error.

If you want to trace this type of error then add the following code in your server-side web.config

<system.diagnostics>
 <sources>
  <source name="System.ServiceModel" switchValue="Information, ActivityTracing"    propagateActivity="true">
   <listeners>
     <add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener"      initializeData= "D:\Traces.svclog"/>
   </listeners>
  </source>
 </sources>
</system.diagnostics>

I think it will help you.

Answer 2

I was able to solve the problem.

If you are using EF "code first"-approach and you want access to your data using WCF you should consider not enabling lazy loading using the "virtual" keyword in your poco-class because WCF serialization cannot serialize dynamic proxy data.