IIS Application Initialization for IIS 7.5 enables website administrators to improve the responsiveness of their Web sites by loading the Web applications before the first request arrives. By proactively loading and initializing all the dependencies such as database connections, compilation of ASP.NET code, and loading of modules, IT Professionals can ensure their Web sites are responsive at all times even if their Web sites use a custom request pipeline or if the Application Pool is recycled. While an application is being initialized, IIS can also be configured to return an alternate response such as static content as a placeholder or "splash page" until an application has completed its initialization tasks.
Note: Application Initialization is built-in for IIS 8.0. For more information, see IIS 8.0 Application Initialization.
Improved customer experience while the Application is warming up
IIS Application Initialization empowers developers to manage the experience that users see when they request an application that is not initialized. The developer can specify a set of URLs to execute to initialize an application, and IIS can be configured to return an alternate response such as static content until the application is finished initializing.
Decrease the response time for first requests by pre-loading worker processes
IIS Application Initialization allows website administrators to configure a web application to be pre-loaded as soon as the worker process starts, before the first request arrives. By pre-loading the application, the worker process is able to reduce the time it takes to respond to the first request. The loading and initialization of the dependencies such as database connections, .NET Framework, and the just-in-time compilation for ASP.NET applications and dependencies have already been performed by the time the request arrives to the server.
Increase reliability by pre-loading worker processes when Overlapped Recycling occurs
The response times for the first requests in an Overlapped Recycling scenario are reduced by also pre-loading dependencies. The recycled worker process will only communicate its readiness and will start accepting requests after it finishes loading and initializing the resources as specified by the configuration.