Smooth Streaming Page
Applies To: Windows 7, Windows Server 2008, Windows Server 2008 R2, Windows Vista
Use this feature page to configure cache options and values that increase Web server performance, reduce latency in the HTTP response to clients, and control how clients can cache the Smooth Streaming content that they receive.
UI Element List
The following tables describe the UI elements that are available on the feature page and in the Actions pane.
Server Cache Settings
Use the Server Cache Settings area to configure output caching to improve Web server performance and reduce latency in the HTTP response to clients.
| Element Name | Description | ||
|---|---|---|---|
Enable server cache |
Enables caching of Smooth Streaming presentation data (metadata and content indexes) using the Output Caching feature settings in IIS Manager. For more information about how to configure output caching, see Configuring Output Caching in IIS 7.
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Freshness check interval |
Enter a time, in seconds, that specifies how often cached Smooth Streaming data should be compared to the original data sources in the file system. If the comparison reveals that the original data sources have been updated, the cached data is deleted. By default, the comparison is performed every 5 seconds. |
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NoteFragment Metadata Memory
Use the Fragment Metadata Memory area to specify the amount of server memory to use for caching Smooth Streaming fragment data (metadata and indexes). When clients request a Smooth Streaming presentation, fragment data can be stored in memory. This enables the Smooth Streaming feature to quickly retrieve MP4 video fragments from the file system for subsequent client requests. The settings enforce a least-recently-used (LRU) algorithm so that the oldest Smooth Streaming fragment metadata is overwritten when the cache is full.
Note
These settings do not enable caching of Smooth Streaming video fragments. To cache fragments, you must specify threshold values in the Fragment Cache Threshold area on this page.
| Element Name | Description |
|---|---|
Limit memory used for fragment metadata |
Clear this check box to use the server’s default cache size for caching Smooth Streaming fragment metadata. If you want to specify the amount of memory to use, select this check box, and then enter a value in Fragment metadata memory limit. |
Fragment metadata memory limit |
If you want to specify the amount of memory to use for caching Smooth Streaming fragment metadata, select the Limit memory used for fragment metadata check box, and then enter the amount of memory to use, in bytes. |
Fragment Cache Threshold
Use the Fragment Cache Threshold area to create a fragment-caching threshold rule that specifies which video fragments are cached. Cached fragments do not have to be reprocessed from the Smooth Streaming source files before they are delivered to clients. This can improve Web server performance and reduce response latency.
Note
Specify threshold values that exclude less frequently requested fragments from being cached. If you create a threshold value that is too low (for example, by requiring that only a few requests for fragments occur during a lengthy request interval), the increased disk I/O operations that occur when Smooth Streaming tries to cache lots of fragments can decrease performance.
If you set the value for Number of requests to 1, all requested fragments are cached, which can significantly impact performance.
| Element Name | Description |
|---|---|
Number of requests |
Enter the number of times a fragment must be requested within the Request interval before it is cached. |
Request interval |
Enter the time, in seconds, during which requests for a fragment are accumulated. If the total accumulation of requests for a particular fragment exceeds the Number of requests value within this request interval, then the fragment is cached. |
Client Cache Settings
Use the Client Cache Settings area to control how client browsers and proxy servers cache the Smooth Streaming content returned by the Web server.
| Element Name | Description |
|---|---|
Enable client cache |
Enables caching of content by clients, according to caching rules specified in Cache-Control header. |
Cache-Control header |
Enter a Cache-Control header directive to be included in the HTTP header response sent to clients. The Cache-Control header directive specifies the conditions and restrictions for caching Smooth Streaming content on the client. For a list of valid directives that you can enter, see Cache-Control. |
Actions Pane Elements
| Element Name | Description |
|---|---|
Apply |
Applies the changes that you made. |
Cancel |
Cancels the changes that you made. |