HttpWebRequest maintenance and http web errors causing it to return "HRESULT E_FAIL" and "server not found" - rest

Question

I am iterating through a large list of objects (1503) and calling a save method on a ServiceProxy I have written. The service proxy uses the new networking stack in Silverlight 4 to call BeginGetRequestStream to start the process of asynchronously sending my objects to an azure REST service I have written for saving off the objects. The Http method I am using is POST. I know HttpWebClient is smart enough to reuse the Http connection so I am not concurrently opening 1503 connections to the server. Saving works fine and all 1503 objects are saved very quickly. However, when I try to save the same objects again, I expect to recieve an HttpStatus code of forbidden because the objects already exist and that is the code I set my azure web service to return. On small groups of objects, it works as expected. However, when I try saving the entire list of 1503 objects, I receive only 455 correct responses and 1048 errors such as "server not found" and
System.Exception ---> System.Exception:Error HRESULT E_FAIL has been returned from a call to a COM component.
at
System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)...
I wonder if there is some sort of book keeping or maintenance I am supposed to be performing on my HttpWebClient instances that I am neglecting and that is what is causing the http errors to throw exceptions but the new saves to work perfectly. Here is my code for handling the error cases:
private static void SendAncestorResponseCallback(IAsyncResult result)
{
var info = (SendAncestorInfo)result.AsyncState;
try
{
var response = info.Request.EndGetResponse(result);
info.Response = response;
}
catch ( Exception ex)
{
info.Error = ex;
}
info.MainThreadContext.Post(SendAncestorMainThreadCallback, info);
}
private static void SendAncestorMainThreadCallback(object state)
{
var info = (SendAncestorInfo)state;
IAncestor origAncestor = info.Content;
HttpWebResponse response = null;
if (info.Error != null)
{
if ((info.Error as WebException) == null)
{
info.Callback(false, origAncestor, null, info.Error);
return;
}
else //get response from WebException
{
response = (HttpWebResponse)(info.Error as WebException).Response;
}
}
else //get response from info.Response
{
response = info.Response as HttpWebResponse;
}
if (response.StatusCode == HttpStatusCode.Created || response.StatusCode == HttpStatusCode.Forbidden)
{
var stream = response.GetResponseStream();
using (var reader = new StreamReader(stream))
{
IAncestor retAncestor = XMLSerializerHelper.DeserializeObject<Ancestor>(reader.ReadToEnd());
info.Callback(response.StatusCode == HttpStatusCode.Created, origAncestor, retAncestor, null);
}
}
else info.Callback(false, origAncestor, null, info.Error);
}
considering how the web service is written I should only expect http status codes of created or forbidden and like I said with small groups this is the case. The fact that I only start getting the errors mentioned earlier makes me feel like I am doing something wrong with the HttpWebRequest objects etc. Any assistance would be greatly appreciated. Thanks.
--update here is the code that generates the HttpWebRequest:
foreach (IAncestor ancestor in ancestors)
{
AncestorViewModel ancestorVM = new AncestorViewModel(ancestor);
ancestorVM.Status = SaveStatus.Undefined;
ParsedAncestors.Add(ancestorVM);
_service.CreateAncestor(UserSrc, ancestor, (success, origAncestor, retAncestor, exception) =>
{
AncestorViewModel result = ParsedAncestors.First(a => a.Model.IdNo == origAncestor.IdNo);
if (exception == null)//web response was either Created or Forbidden
{
if (success)//Ancestor successfully created
{
savedAncestors++;
SuccessMessage = string.Format("{0} Saved\n", savedAncestors);
result.Status = SaveStatus.Saved;
}
else //Ancestor already existed
{
conflictAncestors.Add(origAncestor, retAncestor);
ConflictMessage = string.Format("{0} Conflicts\n", conflictAncestors.Count);
result.Status = SaveStatus.Conflicted;
}
}
else //Show exception recieved from remote web service
{
//if (exception as WebException != null)
//{
// //if exception is WebException get status code and description
// HttpWebResponse rs = (HttpWebResponse)(exception as WebException).Response;
// Message += string.Format("WebServer returned status code {0}: '{1}'\n", (int)rs.StatusCode, rs.StatusDescription);
//}
errors.Add(origAncestor, exception);
ErrorMessage = string.Format("{0} Errors\n", errors.Count);
result.Status = SaveStatus.Error;
}
});
}
public void CreateAncestor(string userSrc, IAncestor ancestor, Action<bool, IAncestor, IAncestor, Exception> callback)
{
WebRequest.RegisterPrefix("http://", WebRequestCreator.ClientHttp);
var request = (HttpWebRequest)WebRequest.Create(
new Uri(string.Format("{0}/{1}/{2}", rootUri, AncestorsRestPoint, userSrc)));
request.Method = "POST";
request.ContentType = "application/xml";
var info = new SendAncestorInfo
{
Request = request,
Callback = callback,
Content = ancestor,
MainThreadContext = SynchronizationContext.Current
};
request.BeginGetRequestStream(SendAncestorRequestCallback, info);
}