Wednesday, June 18, 2008 2:13 PM Dries Marckmann

Sudden Application pool shutdown / 503 service unavailable

Today I suddenly had our web-site shutting down on us. It gave me a  Http Error 503 while it all worked fine a minute earlier.

Service unavailable

I checked IIS (IIS7 in our case) and I saw the Application pool had shut down. We couldn't understand how the application pool could just shutdown. This could potentially shutdown hundreds of sites in one go.

Apparently there is an option in IIS that will shutdown an application pool after 5 errors within 5 minutes, called Rapid-Fail Protection.

image

Disable this feature and your application pool will keep on running.

Leave a Comment

(required) 
(required) 
(optional)
(required)