IIS Windows Process Activation Service (WAS)

Applies To: Windows Server 2008

Windows Process Activation Service (WAS) manages application pool configuration and the creation and lifetime of worker processes for HTTP and other protocols. The World Wide Web Publishing Service (W3SVC) and other services depend on WAS.

Managed Entities

The following is a list of the managed entities that are included in this managed entity:

Name Description

IIS Application Pool

An Internet Information Services (IIS) application pool is a grouping of URLs that is routed to one or more worker processes. Because application pools define a set of Web applications that share one or more worker processes, they provide a convenient way to administer a set of Web sites and applications and their corresponding worker processes. Process boundaries separate each worker process; therefore, a Web site or application in one application pool will not be affected by application problems in other application pools. Application pools significantly increase both the reliability and manageability of a Web infrastructure.

IIS Protocol Adapter

An Internet Information Services (IIS) protocol adapter is a Windows service that receives messages on a specific network protocol and communicates with The Windows Process Activation Service (WAS) to route incoming messages to the correct worker process.


The following is a list of all aspects that are part of this managed entity:

Name Description

IIS WAS Availability

The Internet Information Services (IIS) Windows Process Activation Service (WAS) is needed for most Web sites because it supports the World Wide Web Publishing Service (W3SVC), which handles HTTP requests. The WAS Process Manager maps application pools to existing worker processes and spawns new instances of W3SVC to host new application pools as needed. If WAS is not available, most Web sites will not start.

IIS WAS Configuration

The Internet Information Services (IIS) Windows Process Activation Service (WAS) configuration manager manages configuration for the application pools and protocol adapters that it maintains. If WAS encounters problems when it reads configuration or reacts to configuration change notifications, configuration changes for the entities it manages may not be processed.

IIS Worker Process Dynamic Idle

The Internet Information Services (IIS) Worker Process Activation Service (WAS) can dynamically adjust the idle time-out of worker processes based on current load. You can specify the maximum number of worker processes that can run concurrently on a Web server. If the maximum number is reached and dynamic idle is enabled, WAS dynamically reduces the idle time-out. This could allow new worker processes to start sooner and prevent the Web server from becoming unresponsive.

Internet Information Services (IIS) 7.0