title: Plot.ly data streaming fails after random period of time
body: <p>I've implemented simple rest client for Plot.ly Streaming API, which sends temperature measurements every 5 seconds. All works fine, but at some point process just stops and new dots are not appearing. This can happen withing 15 minutes after start or 1 hour. Tcp connection remains open, underlying stream remains writable, but new points just not showing on the graph. I figured out empirically that Content-Length header has impact on that - if it's large - all works fine for a loner period.</p>
  
  <p>My client is written in C#. Basically i'm writing to opened NetworkStream raw Http request:</p>
  
  <pre><code>private static string GetStringRequest(string host, string token, string data)
  {
          var sb = new StringBuilder()
              .AppendLine($"POST http://{host}/ HTTP/1.1")
              .AppendLine($"Host: {host}")
              .AppendLine("Connection: keep-alive")
              .AppendLine("Content-Type: application/json")
              .AppendLine("Content-Length: " + Int64.MaxValue)
              .AppendLine("Cache-Control: no-cache")
              .AppendLine($"plotly-streamtoken: {token}")
              .AppendLine("")
              .AppendLine("")
              .Append(data);
  
          return sb.ToString();
  }
  
  // this is called every 5 seconds
  public void WriteMeasurement(float value, DateTime dateTimeUtc)
  {
          var data = GetData(...);
          var request = GetStringRequest(Host, _token, data);
  
          _writer.Write(request); // network stream writer
  }
  </code></pre>