title: Occasional gRPC unknown errors when running inside docker container
body: <p>I am trying to connect with a gRPC server running inside a docker. However, I get the below errors sometimes:</p>
  <pre><code>File &quot;xxx/grpc/_channel.py&quot;, line 826, in __call__
      return _end_unary_response_blocking(state, call, False, None)
    File &quot;xxx/grpc/_channel.py&quot;, line 729, in _end_unary_response_blocking
      raise _InactiveRpcError(state)
  grpc._channel._InactiveRpcError: &lt;_InactiveRpcError of RPC that terminated with:
      status = StatusCode.UNKNOWN
          details = &quot;Error in service handler!&quot;
  debug_error_string = &quot;{&quot;created&quot;:&quot;@1599177910.752607903&quot;,&quot;description&quot;:&quot;Error received from peer ipv6:[::1]:50096&quot;,&quot;file&quot;:&quot;src/core/lib/surface/call.cc&quot;,&quot;file_line&quot;:1062,&quot;grpc_message&quot;:&quot;Error in service handler!&quot;,&quot;grpc_status&quot;:2}&quot;
  </code></pre>
  <p>Interestingly, it is an inconsistent failure and doesn't happen every time. I am able to connect with the server in the container successfully a few times. This failure is random and happen roughly once in every 5 times. Can anyone provide some pointers on this failure? Thanks.</p>