scheme Element for httpCompression [IIS Settings Schema]

Configures the GNU zip (Gzip) and Deflate compression schemes.

Syntax

Attributes and Elements

The following sections describe attributes, child elements, and parent elements for this section.

Attributes

Attribute

Description

dll

Required string attribute.

Specifies the fully qualified file system path and file name of the compression DLL associated with the compression scheme. The World Wide Web Publishing Service (WWW service) must be restarted before any changes to this attribute take effect.

doDynamicCompression

Optional Boolean attribute.

Specifies whether responses to requests for dynamic content, such as scripts in Active Server Pages (ASP) and ISAPI extensions, are compressed. Because this attribute cannot be inherited, it must be set to true at both the global level (httpCompression) and at the individual scheme level if the name attribute is set to Gzip. If this value is changed at the individual compression scheme level, the WWW service must be restarted before the change takes effect.

The default value is true.

doStaticCompression

Optional Boolean attribute.

Specifies whether IIS compresses responses to requests for static content. Because this attribute cannot be inherited, it must be set to true at both the global level (httpCompression) and the individual scheme level if the name attribute is set to Gzip. If this value is changed at the individual compression scheme level, the WWW service must be restarted before the change takes effect.

Note

The static compression store needs to be located in a disk partition or remote share formatted with NTFS. If the file store is not NTFS, static compression is disabled. For security reasons, no compressed responses will be served from a FAT cache store.

The default value is true.

dynamicCompressionLevel

Optional integer attribute.

Specifies the compression level for the compression scheme when dynamic content is being compressed. The levels range from 0 (lowest compression level and lowest CPU usage) to 10 (highest compression level and highest CPU usage). 0 means that compression is disabled. The WWW service must be restarted before any changes to this attribute take effect.

Note

Because dynamic compression consumes considerable CPU time and memory resources, use it only on servers that have slow network connections but CPU time to spare. Compressed static responses can be cached and, therefore, do not affect CPU resources like dynamic responses do.

The default value is 0.

name

Required string attribute.

Specifies the name of the compression scheme, for example, Gzip or Deflate.

staticCompressionLevel

Optional integer attribute.

Specifies the compression level for the compression scheme when static content is being compressed. The levels range from 0 (lowest compression level and lowest CPU usage) to 10 (highest compression level and lowest CPU usage). 0 means that compression is disabled. The WWW service must be restarted before any changes to this attribute take effect.

The default value is 7.

Child Elements

Element

Description

remove

Optional element.

Removes a reference to an HTTP compression scheme from the HTTP compression scheme collection.

clear

Optional element.

Removes all references to HTTP compression schemes from the HTTP compression scheme collection.

Parent Elements

Element

Description

configuration

Specifies the root element in every configuration file that is used by IIS 7.

system.webServer

Specifies the root element in ApplicationHost.config that is the top-level section group in which this element is defined.

httpCompression

Configures HTTP compression settings for a Web server.

Remarks

For more information about the scheme element, see the following topic on the Microsoft IIS.net Web site: Scheme <scheme>.

Element Information

Configuration locations

Machine.config

ApplicationHost.config

Root level Web.config

Application level Web.config

Virtual or physical directory level Web.config

Requirements

Microsoft Internet Information Services (IIS) version 7.0

See Also

Reference

remove Element for scheme for httpCompression [IIS Settings Schema]

clear Element for scheme for httpCompression [IIS Settings Schema]

Other Resources

Scheme <scheme>