How To Improve Server Performance when Streaming On-Demand Content from a Remote Share (812633)
The information in this article applies to:
- Microsoft Windows Media Services 9 Series
SUMMARYThe Window Media Services 9 Series is tuned, by default, for
best performance during typical user scenarios. This article describes a
setting in the Windows Media Services 9 Series Server (WMS) that may improve
performance in the following situation: when the WMS Server is streaming media
content that is located on a remote share (for example, a SAN or a NAS) to
on-demand clients.MORE INFORMATIONWhen streaming from a file on the local disk, the OS file
system cache manager will buffer blocks of the file in memory. This helps
improve performance by reducing disk I/O operations. However, when accessing
content on a remote share, this OS file system caching process may not always
occur. This behavior occurs because WMS Server allows files to be opened in a
sharing mode. This sharing mode then allows other applications to read, modify,
and delete files while in use by WMS.
Under these circumstances, the
OS file system cache manager may not be able to buffer remote files. As a
result, every client request is served from the remote share. This can put
increased demands on the network, increase disk I/O operations, and increase
CPU usage on the WMS server.
Note Do not make these changes until you determine the effects on the
overall server performance and to the end user experience. In addition to
affecting the files that are being read, the server also prevents files in the
whole remote folder where the content is located from being modified.
Therefore, users cannot modify or add content to this share while clients are
streaming from any file in the share.WORKAROUNDWarning This article contains information about editing the namespace.
Before you edit the namespace, verify that you have a backup copy that you can
restore if a problem occurs. If you edit the namespace incorrectly, you can
cause serious problems that may require you to reinstall any product that uses
the namespace. Microsoft cannot guarantee that problems that result if you
incorrectly edit the namespace can be solved. Edit the namespace at your own
risk.
A setting in the WMS Server Namespace can be set to
disallow shared writing on the file it opens. This setting can make sure that
the OS file system cache manager caches blocks of the remote file in the memory
on the WMS Server. To change this setting, follow these steps:
- Stop the Windows Media Services (run the net stop wmserver command).
- Change to the directory where the namespace file is
located (%SystemRoot%\system32\windows media\server).
- Open the ServerNamespace.xml file in a text editor, such
as Notepad.
- Locate the WMS File Data Source node in the namespace, and then expand the Properties node.
- Add the following value below the Properties sub-node:
- Only File Read Share- Sets whether this property is enabled (0x1) or disabled
(0x0).
<node name="Only File Read Share" opcode="create" type="int32" value="0x1" /> - Save and then close the file.
- Restart Windows Media Services (run the net start wmserver command).
The following is another representation of the code that you can
add to the ServerNamespace.xml file: <node name="WMS File Data Source" opcode="create" >
...
<node name="Properties" opcode="create" >
...
<node name="Only File Read Share" opcode="create" type="int32" value="0x1" />
</node> <!-- Properties -->
...
</node> <!-- WMS File Data Source -->
After you enable this property, the WMS Server opens files on the remote
share in a mode that does not allow other files to write to them. Because other
users or applications cannot modify this file, the OS file system cache manager
on the WMS Server caches the file to local memory. Before you enable this
setting, see the Note in the "More Information" section of this
article.
| Modification Type: | Minor | Last Reviewed: | 10/11/2004 |
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| Keywords: | kbDSWWMM2003Swept kbhowto kbinfo KB812633 kbAudDeveloper kbAudITPRO |
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