Bundled files created constantly

[optional]

We're using version 0.9.8.0 of SquishIt.Framework. Starting about 2017-03-07, SquishIt constantly recreates the same files. The files that make up the bundle haven't changed. It seems like they are never available in the HttpRuntime cache, even though we see that the SquishIt code adds them. There are otherwise no signs of memory issues in the application.

Each time render is called on the page a new file is generated. We see waits of 20+ seconds in SquishIt.Framework.Base.BundleBase.RenderRelease after it creates an instance of CriticalRenderingSection. The time is spent waiting for the mutex to be released.

There have been no recent code changes, so we're wondering if there may be a recent Windows update that somehow affected SquishIt.

[AlexCuse]

I presume you aren't seeing a lot of app pool recycling or similar?

A few details about your situation could help track this down:

Windows/.net framework/iis versions
Deployment situation (shared hosting, vm or dedicated physical hardware)
Rendering details (are you creating bundles inline, pre-rendering into cache on startup, etc...)
Also are you rendering combined files locally or on a CDN?
Are you using .less, coffee script or any other preprocessors?