For some reasons my server response time is 18 seconds for one of the pages in my ASP.NET MVC application.
How can I check which operation is taking that long? I want to know in what point of the application lifecycle the time is being wasted.
Is there some third-party extension for VS or may be a build in feature of the VS debugger to find out what I need?
Use Glimpse, which has support for ASP.NET MVC 2, ASP.NET MVC 3 and ASP.NET MVC 4 via Extensions.
You will be primarily interested in the Execution
tab, as it will show how long each controller action is taking to execute, which will let you dig into the "slow" ones, like this: