ASP.NET MVC intermittent slow response

Question

Problem

In our production environment, system occasionally delays the page response of an ASP.NET MVC application up to 30 seconds or so, even though same page renders in 2-3 seconds most of the times. This happens randomly with any arbitrary page, and GET or POST type requests. For example, log files indicates, system took 15 seconds to complete a request for jquery script file or for other small css file it took 10 secs.

Similar Problems:

1. Random Slow Downs

Production Environment:

1. Windows Server 2008 - Standard (32-bit) - App Pool running in integrated mode.
2. ASP.NET MVC 1.0

We have tried followings/observations:

1. Moved the application to a stand alone web server, but, it didn't help.
2. We didn't ever notice same issue on the server for any 'ASP.NET' application.
3. App Pool settings are fine. No abrupt recycles/shutdowns.
4. No cpu spikes or memory problems.
5. No delays due to SQL queries or so.
6. Converting App Pool to classic mode didn't help either

It seems as something causing delay along HTTP Pipeline or worker processor seeing the request late.

Looking for other suggestions.

-- Thanks

Answer 1

Sorry if this is too obvious but have you checked IIS? for Process recycling, you can set it so it recycles once a day at a set time .

You could also try application warm up http://weblogs.asp.net/gunnarpeipman/archive/2010/01/31/asp-net-4-0-how-to-use-application-warm-up-class.aspx