Before IIS 8.5, Internet Information Services (IIS) automatically activates all configured websites. For a system with a large number of sites configured, it not only takes a lot of time and resources to activate all those sites at once, but the sites can use a large amount of memory.
In IIS 8.5, when there are a large number of configured sites (100 or greater, by default), the service will not activate any of the sites when the service is started. Instead, IIS will activate each site only when it receives the first request for the site. This reduces the amount of system resources required by IIS.
- Idle Worker Process Page-out
IIS terminates a worker process that is idle for a specified period of time (20 min is the default). Next time the site is accessed, the user will need to wait for the worker process to start again. In IIS 8.5, the administrator has the option of suspending an idle worker process rather than terminating it. A suspended worker process remains alive but is paged-out to disk, reducing the system resources it consumes. When a user accesses the site again, the worker process wakes up from suspension and is quickly available.
In IIS 8.5, the administrator has the option of logging additional custom fields from request or response headers, or from server variables.
Once the custom fields have been configured, IIS will create new text log files with "_x" appended to the file name to indicate that the file contains custom fields.
Note that the total size of data collected from all custom fields cannot exceed 65,536 bytes. If the total exceeds 65,536 bytes, then IIS will truncate the data.
In IIS 8.5, the administrator has the option of sending logging information to Event Tracing for Windows (ETW). This option gives the administrator the ability to use standard query tools, or create custom tools, for viewing real-time logging information in ETW. This provides a significant advantage over parsing text-based log files that are not updated in real time.
To learn more about IIS 8.5, please visit www.iis.net/learn. Wade & Erez has a presentation on TechEd on channel 9 about IIS: new scalability & manageability features.