Microsoft Internet Information Server IIS Application Pools & Worker Processes 2 — Questions and Answers
Question 1: What does the '.NET CLR version' setting in an IIS application pool specify?
- The Windows Server version required for compatibility
- Which version of the .NET framework the pool uses to run managed code (Correct answer)
- The CLR memory allocation limit for the worker process
- The timeout for .NET runtime initialization during pool startup
Correct answer: Which version of the .NET framework the pool uses to run managed code
The .NET CLR version setting selects which version of the .NET framework (such as v2.0 or v4.0) the application pool will load to execute managed code.
Question 2: What does the 'Rapid Fail Protection' feature do in an IIS application pool?
- Speeds up worker process startup by pre-loading common assemblies
- Disables an application pool after repeated worker process failures within a time window (Correct answer)
- Distributes load to healthy pools when the primary pool becomes overloaded
- Activates a backup application pool when the primary pool fails
Correct answer: Disables an application pool after repeated worker process failures within a time window
Rapid Fail Protection disables an application pool when its worker process fails more than a configured number of times within a set period, preventing resource exhaustion from repeated crash loops.
Question 3: Which application pool identity runs with the least privilege for hosting IIS applications?
- Local System
- Network Service
- Local Service
- ApplicationPoolIdentity (Correct answer)
Correct answer: ApplicationPoolIdentity
ApplicationPoolIdentity creates a unique, automatically managed virtual account per pool with only the permissions needed to run the pool, making it the most restrictive and recommended identity.
Question 4: What does the 'Queue Length' setting control in an IIS application pool?
- The maximum number of concurrent database connections the pool may use
- The maximum number of HTTP requests that can queue for the pool before a 503 error is returned (Correct answer)
- The number of worker processes that can run simultaneously in the pool
- The number of idle timeout checks IIS performs before shutting down a worker process
Correct answer: The maximum number of HTTP requests that can queue for the pool before a 503 error is returned
Queue Length sets the maximum number of pending HTTP requests that can wait for an available worker process before IIS returns a 503 Service Unavailable response.
Question 5: Which Windows event log should administrators check when an IIS application pool fails to start?
- System Log
- Application Log (Correct answer)
- Security Log
- Setup Log
Correct answer: Application Log
Application pool startup failures and worker process errors are recorded in the Windows Application Event Log, typically under the IIS-W3SVC-WP source.
Question 6: What does the 'Always Running' startup mode do when configured for an IIS application pool?
- Prevents the application pool from ever being recycled
- Starts the worker process at system startup before any requests arrive (Correct answer)
- Enables continuous load balancing across all configured application pools
- Forces the pool's worker process to run at the highest CPU scheduling priority
Correct answer: Starts the worker process at system startup before any requests arrive
'Always Running' pre-warms the application pool by starting the worker process when IIS starts, eliminating cold-start delays on the first incoming request.
Question 7: When hosting a 32-bit application on a 64-bit IIS server, which application pool setting must be enabled?
- Enable Protocol Activation
- Enable 32-Bit Applications (Correct answer)
- Enable Kernel-Mode Authentication
- Enable Preload
Correct answer: Enable 32-Bit Applications
The 'Enable 32-Bit Applications' setting must be set to True so that IIS runs the worker process as a 32-bit process capable of loading 32-bit managed and native assemblies.
Microsoft Internet Information Server IIS Application Pools & Worker Processes 2
What does the '.NET CLR version' setting in an IIS application pool specify?