IIS App Pool cannot recycle when there is an open ASP.NET 4.5 Websocket

Question

I have run into an issue which can be replicated in the following way (you need IIS8 so must be on Windows 8+ or Windows Server 2012 R2+):

Create a new website in IIS Ma

Answer 1

Try setting "Shutdown Time Limit" to 1 second (App Pool > Advanced Settings > Process Model) [PS: I don't have IIS8. I'm checking the properties in IIS7.]

This property defines the time given to worker process to finish processing requests and shutdown. If the worker process exceeds the shutdown time limit, it is terminated.

I can see default value in IIS7 is 90 seconds. If that's the same value in IIS8 too, then it might be giving that much time to earlier worker process to finish it's work. After 90 seconds (1.5 mins) it will terminate that process and your web socket will get closed. If you change it to 1 second it will terminate the earlier worker process will get terminated almost instantly (as soon as you recycle app pool) and you will get the expected behavior.