“Specified network name is no longer available” in Httplistener


I have built a simple web service that simply uses HttpListener to receive and send requests. Occasionally, the service fails with "Specified network name is no longer available". It appears to be thrown when I write to the output buffer of the HttpListenerResponse.

Here is the error:

ListenerCallback() Error: The specified network name is no longer available at System.Net.HttpResponseStream.Write(Byte[] buffer, Int32 offset, Int32 size)

and here is the guilty portion of the code. responseString is the data being sent back to the client:

buffer = System.Text.Encoding.UTF8.GetBytes(responseString);

response.ContentLength64 = buffer.Length;
output = response.OutputStream;
output.Write(buffer, 0, buffer.Length);

It doesn't seem to always be a huge buffer, two examples are 3,816 bytes and, 142,619 bytes, these errors were thrown about 30 seconds apart. I would not think that my single client application would be overloading HTTPlistener; the client does occasionally sent/receive data in bursts, with several exchanges happening one after another.

Mostly Google searches shows that this is a common IT problem where, when there are network problems, this error is shown — most of the help is directed toward sysadmins diagnosing a problem with an app moreso than developers tracking down a bug. My app has been tested on different machines, networks, etc. and I don't think it's simply a network configuration problem.

What may be the cause of this problem?

Best Solution

I'm getting this too, when a ContentLength64 is specified and KeepAlive is false. It seems as though the client is inspecting the Content-Length header (which, by all possible accounts, is set correctly, since I get an exception with any other value) and then saying "Whelp I'm done KTHXBYE" and closing the connection a little bit before the underlying HttpListenerResponse stream was expecting it to. For now, I'm just catching the exception and moving on.

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