IIS 6.0 F1: Application Pools Properties - Performance Tab
Applies To: Windows Server 2008 R2
Use this tab to configure the way that Internet Information Services (IIS) shuts down idle worker processes, the number of requests waiting to be processed, CPU monitoring, and the number of processes in a Web garden.
Idle timeout limits helps conserve system resources by terminating unused worker processes by gracefully closing idle processes after a specified idle duration. This allows you to better manage the resources on particular computers when the processing load is heavy, when identified applications consistently fall into an idle state, or when new processing space is not available.
Shutdown worker processes after being idle for (time in minutes)
Select to terminate any idle worker processes after a specific period of inactivity.
Type a number in the box, or click the up and down arrows, to set the amount of minutes before an idle worker process terminates.
Request queue limit
Select to configure IIS to monitor the number of requests for a designated application pool queue before queuing a new request.
Application pool queue length limits prevent large numbers of requests from queuing up and overloading your server. If adding the new request to the queue exceeds the capacity of the queue, the server rejects the request and sends a non-customizable 503-error response to the client.
Limit the kernel request queue (number of requests)
Select to configure IIS to use a numeric-based scheme for limiting incoming HTTP requests and allow you to limit the size of the request queue. When the limit is reached, IIS does not process those additional requests, but sends a non-customizable 503-error response to the client.
Type a number in the box, or click the up and down arrows, to set the limit for the number of requests allowed in the queue.
Enable CPU monitoring
Select to configure IIS to use CPU accounting to track and terminate worker processes that consume large amounts of CPU time that exceed the specified limits. CPU monitoring is available only for applications pools and does not apply to CGI applications.
Maximum CPU use (percentage)
Type a number in the box, or click the up and down arrows, to set the percentage of CPU usage a worker process is permitted to use.
Refresh CPU usage numbers (in minutes)
Type a number in the box, or click the up and down arrows, to set how often CPU process numbers are to be refreshed in order to be used by CPU monitoring.
Action performed when CPU usage exceeds maximum CPU use
From the list box, click the best action to perform when the CPU exceeds its specified maximum usage.
If No action is selected, when the CPU usage for a specific application pool or group of pools reaches the set limit, IIS writes an error in the Event Log.
If Shutdown is selected, when the CPU usage for a specific application pool reaches the set limit, IIS initiates a shutdown of all worker processes in the application pool by allowing each worker process the application pool's specified ShutdownTimeLimit seconds to shut down. If the processes do not shut down in that time frame, IIS terminates the worker processes. The application pool shuts down and resets according to the time limit set in CPUResetInterval.
A Web garden is an application pool using more than one worker process.
Maximum number of worker processes
Type a number in the box, or click the up and down arrows, to set the maximum number of worker processes allowed within an application pool.
To learn more about the timeout and CPU features, and about Web gardens, see the IIS 6.0 online documentation on the Microsoft Windows Server TechCenter.