During recent load testing we observed slow response with one of key web pages. Regardless of the load – single user or multiple users – the response time wasn’t of satisfactory and varied between 8 to 18 seconds depending on the environment.
Inspecting the call stack we have noticed the call to System.Net.Dns.GetHostEntry(System.Net.IPAddress). This triggered our thinking that DNS translation latency could be at play.
Quick search on the web revealed this post –
Ta validate our assumption – that the latency is caused by the DNS translation – we created the registry entry and configured the timeouts to minimum values and then re-run the load tests. Next thing you know the response times were directly affected and faster in half.
The decision was to remove this functionality altogether, since it was introduced to make the log entries look friendlier vs. just IP.