WWW Service Administration and Monitoring
Applies To: Windows Server 2003, Windows Server 2003 with SP1
The WWW Service Administration and Monitoring component, which is hosted in Svchost.exe, is a set of new features contained in the WWW service. Like the worker process, this new component runs in user mode, and like HTTP.sys, this component contains critical IIS 6.0 functionality that never loads external code. IIS 6.0 completely isolates external application code from this component by running only the external code in worker processes.
Note
Because the WWW Service Administration and Monitoring component implements and controls a set of new features contained in the WWW service, to simplify the text, the term WWW service is used when discussing these new features instead of the term WWW Service Administration and Monitoring component.
The WWW service is responsible for two roles in IIS: HTTP administration and worker process management.
HTTP administration
The WWW service interacts with the metabase to obtain the configuration data that is needed to set up HTTP.sys and that is used to manage the worker process.
When you start a server that is running IIS, and the WWW service is started, this service reads metabase information and initializes the HTTP.sys namespace routing table with one entry for each application. HTTP.sys then uses the routing table data to determine which application pool responds to requests from what parts of the namespace. When HTTP.sys receives a request, it signals the WWW service to start a worker process for the application pool.
When you add or delete an application pool, the WWW service processes the configuration changes, which includes adding or deleting the application pool queue from HTTP.sys. The WWW service also listens for and processes configuration changes that occur as a result of application pool recycling.
Managing the lifetime of the worker process
The WWW service is responsible for managing the worker processes, which includes starting the worker processes and maintaining information about the running worker processes. This service also determines when to start a worker process, when to recycle a worker process, and when to restart a worker process if it becomes blocked and is unable to process any more requests.
In worker process isolation mode, the WWW service is responsible for health management and maintenance, including application pool health monitoring, recycling worker processes, and rapid-fail protection. For more information about these new features, see Features of Worker Process Isolation Mode, and Running IIS 6.0 as an Application Server.
The WWW service runs under the Local System account. For more information about Local System accounts, including Windows Server 2003 built-in security accounts, see Running IIS 6.0 as an Application Server and Managing a Secure IIS 6.0 Solution.