Application Pool Health
Ping worker process periodically
This property specifies whether the WWW Publishing Service should periodically monitor the health of a worker process. Checking this option indicates to the WWW service to monitor the worker processes to ensure that they are running and healthy.
Interval between health-monitoring pings
This property specifies the period of time (in seconds) between health-monitoring pings that the WWW Publishing Service sends to a worker process.
The value of this property specifies the amount of time (in seconds) that the WWW Publishing Service should wait for a worker process to finish starting up and reporting to the WWW Service.
The value of this property specifies the amount of time (in seconds) after a recycle threshold has been reached that IIS waits for all old requests to finish running in a worker process before terminating the worker process.
Rapid Fail Protection
Enable Rapid Fail Protection
When enabling Rapid Fail Protection the application pool is shut down if there is a specified number of worker process crashes ("Failure count") within a specified time period ("Time period"). When this happens the WWW Publishing Service puts all applications in the application pool "out of service".
This property specifies the maximum number of failures allowed within the number of minutes specified by the "Time period" property, before the application pool is shut down by Rapid Fail Protection.
This property specifies the number of minutes before the failure count for a process is reset.
You can read more about application pools in this article.