The Windows Process Activation Service (WAS) manages the activation and lifetime of the worker processes that contain applications that host Windows Communication Foundation (WCF) services. The Windows Process Activation Service process model generalizes the IIS process model for the HTTP server by removing the dependency on HTTP. This allows WCF services to use both HTTP and non-HTTP protocols, such as Net.Tcp, in a hosting environment that supports message-based activation, and it provides the ability to host a large number of applications on a computer.
This service is not installed by default. For security, you should not run the Windows Process Activation Service unless your system supports the .NET Framework 3.5.1 application or IIS 7.0. The .NET Framework 3.5.1 and IIS 7.0 automatically install the Windows Process Activation Service as needed. You should not install the Windows Process Activation Service by itself.
When the Windows Process Activation Service is started in its default configuration, it logs on by using the Local System account.
The Windows Process Activation Service is dependent upon on the following system components:
- Remote Procedure Call (RPC)
- DCOM Server Process Launcher
- RPC Endpoint Mapper
The following system components are dependent upon the Windows Process Activation Service:
- Net.Msmq Listener Adapter
- Net.Pipe Listener Adapter
- Net.Tcp Listener Adapter
- World Wide Web Publishing Service