Which requests cause a w3wp process to grow considerably?

Question

On a production environment, how can one discover which Asp.Net http requests, whether aspx or asmx or custom, are causing the most memory pressure within a w3wp.exe process? I don't mean memory leaks here. It's a good healthy application that disposes all it's objects nicely. Microsoft's generational GC does it's work fine. Some requests however, cause the w3wp process to grow its memory footprint considerably, but only for the duration of the request.

It is simply a question of the cost-efficiency and scalability of a production environment for a SAAS app, in order to regularly report back to the development department on their most memory hogging "pages", to return that (memory) pressure where it belongs, so to speak.

There doesn't seem to be anything like:
HttpContext.Request.PeakPrivateBytes or .CurrentPrivateBytes
or
Session.PeakPrivateBytes

Answer 1

You might want to use a tool like Performance Monitor to monitor the "Process\Working Set" for the W3WP.exe process and record it to a database. You then could could correlate it to the HTTP logs for the IIS Server.

It helps to have both the Perfmon data and HTTP logs both writing to an SQL database. Then you can use T-SQL to bring up requested pages by Date/Time around the time of the observed memory pressure. Use the DatePart function to build a Date/Time rounded to the desired accuracy of Second or Minute as needed.

Hope this helps.

Thanks, -Glenn

Answer 2

If you are using InProc session state, all your session data is stored in w3wp's memory, and may be the cause of it growing.

Answer 3

I wouldn't worry about it. It could be that the GC is happening during the request, and the CLR is allocating memory to move things around. Or it could be some other periodic servicing thing that comes along with ASPNET.

Unless you are prepared to go spelunking with perf counter analysis of generation 0,1,2 GC events , and etc, then I wouldn't worry about solving this "problem".

And it doesn't sound like it's a problem anyway - just a curiosity thing.