The Role of the Metabase in IIS
IIS operates from a copy of the metabase that is loaded into memory. When the metabase is altered, configuration changes take effect immediately in the in-memory metabase, but not in the physical metabase files.
The in-memory metabase is written to disk when one of two events occur:
When the IIS administration service (IIS Admin) is stopped.
60 seconds after a configuration change is made unless another 30 configuration changes occurs within that 60 seconds. Each time a new configuration change is made, the timer is reset for another 60 seconds. The timer can be reset a maximum of five times before IIS forces a write to disk.
The previous copy of the metabase on disk is written to a history file when the current in-memory metabase is written to disk.
For detailed architectural and administrative information about the metabase, see the section titled IIS Metabase in the user documentation that comes with IIS.