Question

I’m looking for a way to measure each step of a (HTTP) web request in .NET similar to Firebug’s network waterfall timeline or Pingdom.com’s full page test.

Both share a lowest common denominator of showing time spans required for each request to:

• Lookup DNS
• Connect
• Send the request
• Wait for response
• Receive response

Obviously I can use a timer to measure the web requests GetResponse() and GetResponseStream() methods, but I’m looking for a way to be as granular as possible with as many measurements as possible.

What’s the best way in .NET to measure each stage of the request life cycle?

Thanks!

Answer 1

You might look at ETW tracing to do this. AFAIK ETW tracing output a ton of information from many .NET APIs. At least I see it all the time when I use reflector to browse the .NET framework.

If ETW cannot do this I am pretty sure you can hook many relevant points in the pipeline:

• Lookup DNS: Do the lookup yourself and measure the timing. The HttpWebRequest’s internal lookup will now be served from cache and execute in 0ms.
• Connect: This happend when you call GetRequestStream()
• Send the request: This happens when you call GetRequestStream().Dispose()
• Wait for response: This happens when you call GetResponseStream()
• Receive response: This happens when GetResponseStream().Read() returns 0.