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asp.net-mvcentity-frameworkiis-expressmemory-profiling

dotMemory profiling huge memory difference between iisexpress & WebDev

I'm trying to get a handle on memory usage of my ASP.NET MVC4 / EF5 web application through dotMemory profiling. I'm still confused by what I see, but one thing that concerns me is the large difference in memory between running a profile on IISExpress and WebDev.

At start up, IISExpress shows (* Actually this jumped each time I killed the process and started up the profiler again):

  • Total: 352.3 MB
  • Heap Gen 0: 242.7 MB
  • Heap Gen 1: 3.1 KB
  • Heap Gen 2: 31.5 MB

Whereas WebDev:

  • Total: 180 MB
  • Heap Gen 0: 3 MB
  • Heap Gen 1: 148.2 KB
  • Heap Gen 2: 24.6 MB

This application is hosted on IIS 7.5 so which should I trust? And why does my managed memory go down after a snapshot? This is especially true with IISExpress.

Also I'm having a hard time finding what are real issues I can impact. Things tend to boil down to EF or AutoMapper and I don't see how I can avoid iterator allocation in entity linq queries and CreateMaps, etc. (http://blog.jetbrains.com/dotnet/2014/07/24/unusual-ways-of-boosting-up-app-performance-lambdas-and-linqs/)

What am I not seeing?

Edit

Memory Traffic snapshot -- String is the largest consumer JScript

Lots of byte allocated from using AutoMapper's CreateMap -- any possible remedy? AutoMapper

Solution

  • Heap Gen 0: 242.7 MB

    This is a specific thing of IIS to have a very huge Gen 0 heaps

    And why does my managed memory go down after a snapshot? This is especially true with IISExpress.

    dotMemory forces garbage collecting on getting snapshot (this is how MS profiling API works)

    Also I'm having a hard time finding what are real issues I can impact.

    I would recommend to check if a picture of the memory consumption correlates with a picture "in your head". Check top 5-10 types which objects consumes the greatest amount of the memory. Look at top objects exclusively retains memory. Check an app on memory leaks - all objects are released after a particular activity finishes. If you don't see any very unusual, maybe you do not have to do anything.