<system.applicationHost>

Overview

The <system.applicationHost> element contains global configuration settings that are used by the Windows Process Activation Service (WAS) in Internet Information Services (IIS) 7. This element defines many of the server-level configuration settings in the IIS 7 ApplicationHost.config file.

Of significant importance, the <system.applicationHost> element contains the configuration settings for the <applicationPools> and <sites> collections, which respectively define the collection of application pools and Web sites on an IIS 7 server.

Note: Unlike the settings that are found in <system.webServer>, settings in the <system.applicationHost> element cannot be delegated.

Compatibility

Version Notes
IIS 8.5 The <system.applicationHost> element was not modified in IIS 8.5.
IIS 8.0 The <system.applicationHost> element was not modified in IIS 8.0.
IIS 7.5 The <serviceAutoStartProviders> element was added in IIS 7.5.
IIS 7.0 The <system.applicationHost> element was introduced in IIS 7.0.
IIS 6.0 N/A

Setup

The <system.applicationHost> element is included in the default installation of IIS 7.

How To

There are no examples that are specific to the <system.applicationHost> element. For examples that configure the settings that are found within the <system.applicationHost> element, see the child elements that are listed in the configuration details section of this topic.

Configuration

The <system.applicationHost> element is defined in the ApplicationHost.config file.

Attributes

None.

Child Elements

Element Description
applicationPools Optional element.

Contains default configuration settings for all application pools on the server and defines configuration settings for specific application pools.
configHistory Optional element.

Specifies the configuration history settings for a server.
customMetadata Optional element.

Contains settings that are used internally by the Admin Base Object (ABO) mapper component of IIS 7.
listenerAdapters Optional element.

Specifies configuration settings for listener adapters, which are components that establish communication between non-HTTP protocol listeners and WAS.
log Optional element.

Specifies the logging mode for a server.
serviceAutoStartProviders Optional element.

Specifies a collection of managed assemblies that will be loaded when the AlwaysRunning is specifed for an applocation pool's startMode.

Note: This element was added in IIS 7.5.
sites Optional element.

Defines all sites on the server, and all applications and virtual directories in those sites.
webLimits Optional element.

Configures TCP/IP connection and bandwidth limits.

Configuration Sample

The following configuration sample defines a simple, static-content-only <system.applicationHost> element, with a single application pool ("DefaultAppPool") and a single Web site ("Default Web Site").

<system.applicationHost>
   <applicationPools>
      <add name="DefaultAppPool" />
     <applicationPoolDefaults>
         <processModel identityType="NetworkService" />
      </applicationPoolDefaults>
   </applicationPools>
   <customMetadata />
   <listenerAdapters>
      <add name="http" />
   </listenerAdapters>
   <log>
      <centralBinaryLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
      <centralW3CLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
   </log>
   <sites>
      <site name="Default Web Site" id="1">
         <application path="/">
            <virtualDirectory path="/" physicalPath="%SystemDrive%\inetpub\wwwroot" />
         </application>
         <bindings>
            <binding protocol="http" bindingInformation="*:80:" />
         </bindings>
      </site>
      <siteDefaults>
         <logFile logFormat="W3C" directory="%SystemDrive%\inetpub\logs\LogFiles" />
         <traceFailedRequestsLogging directory="%SystemDrive%\inetpub\logs\FailedReqLogFiles" />
      </siteDefaults>
      <applicationDefaults applicationPool="DefaultAppPool" />
      <virtualDirectoryDefaults allowSubDirConfig="true" />
   </sites>
   <webLimits />
</system.applicationHost>

Sample Code

There are no code samples that are specific to the <system.applicationHost> element. For code samples that configure the settings that are found within the <system.applicationHost> element, see the child elements that are listed in the configuration details section of this topic.

Deprecated Elements