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Disable Rapid Fail Protection

This tutorial will guide you through preventing an Application Pool stopping and not automatically restarting if it crashes. This is useful when your application has a bug which causes the application pool to crash randomly and so often that rapid fail protection prevents it restarting to protect the system. This would normally require manual action to fix, this tutorial will negate that need.

Time to complete: ~2 minutes

Requirements: Working installation of IIS 7.5.


What is Rapid Fail Protection?

Rapid fail protection will prevent a site from recovering if it causes too many errors in a set period of time. This is useful when an application goes out of control which could overload the server.

Why would an application crash the application pool?

There are many reasons, but the most common would be a fault in the application or the interpreter (for example PHP). A rare bug may cause rapid fail protection to kick in.

Why would I want to disable Rapid Fail Protection on IIS 7.5?

By disabling rapid fail protection, you might be able to prevent your site from going down. Normally you would need to restart the application pool manually when rapid fail protection kicks in. By turning it off, you allow unlimited restarts which is especially useful if the problem your application is encountering is rare.

What are the dangers of disabling Rapid Fail Protection?

If the application causes the application pool to go out of control into a loop, you could cause the server unnecessary load, and it might cause so much load that the server greatly slows down or goes down completely. You must out weigh the requirements of the sites hosted on the server vs reliability required.


1. Open the IIS Console

– Go to Control Panel\All Control Panel Items\Administrative Tools and opening Internet Information Services (IIS) Manager.


2. Edit the settings

– Expand the server tree and select Application Pools.

Select the site you want to edit.

– On the right, select Advanced Settings and you will get a dialogue box.

– Scroll down to Rapid Fail Protection.

– Change the option Enabled from true to False.

– Click OK to acknowledge the changes and close the dialogue box.


The application pool should now automatically restart every time it crashes, regardless of how many errors it produces.