private void OnPutSlave(HttpListenerRequest req, HttpListenerResponse res)
{
var dto = req.ReadBody<ClientRequest>();
var slave = req.RemoteEndPoint.Address.ToString();
if (dto.Status == "up")
{
slaves.Add(slave);
}
else if (dto.Status == "down")
{
slaves.Remove(slave);
}
res.Write204();
}
