IIS 7.0: serverRuntime Element (IIS Settings Schema)

<serverRuntime>

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Configures request limits for applications on a Web server.

configuration Element [IIS 7 Settings Schema]
system.webServer Section Group [IIS 7 Settings Schema]
IIS 7.0: serverRuntime Element (IIS Settings Schema)

<serverRuntime 
   enabled="true|false"
   appConcurrentRequestLimit="number of requests"
   uploadReadAheadSize="number of bytes"
   alternateHostName="host name"
   enableNagling="true|false"
   frequentHitThreshold="number of requests"
   frequentHitTimePeriod="time interval"
/>

Attributes and Elements

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

Attributes

Attribute	Description
alternateHostName	Optional string attribute. Specifies the host name to use for redirection.
appConcurrentRequestLimit	Optional uint attribute. Specifies the maximum number of requests that can be queued for an application. The default value is 5000.
enabled	Optional Boolean attribute. Specifies whether applications on the Web server are able to serve content (true) or not are not able to serve content (false). The default value is true.
enableNagling	Optional Boolean attribute. Specifies whether nagling is enabled (true) or disabled (false). The default value is false. Note: Nagling is an optimization for HTTP over TCP that increases efficiency by trying to minimize the number of packets that are required before data is sent. It works by waiting to send a packet until its data area is full, until a 200-millisecond time-out period expires, or until the sender indicates that it is finished sending data. IIS versions 5.1 and earlier use nagling for all data sent to the client.Nagling has a possible downside. If an extension does not fill up the packet, there is still a delay of 200 milliseconds before the response is sent. This behavior is seen most often when you use ISAPI extensions that support an HTTP Keep-Alive header in the response to the client. In this case, IIS does not close the connection after the response, so the final packet ends up waiting for 200 milliseconds.
frequentHitThreshold	Optional uint attribute. Specifies the number of times a URL must be requested, within the time span specified in the frequentHitTimePeriod attribute, to be considered frequently hit. The value must be between 1 and 2147483647. The default value is 2.
frequentHitTimePeriod	Optional timeSpan attribute. Specifies the time interval in which a URL must be requested the number of times specified in the frequentHitThreshold attribute before it is considered to be frequently hit. The default value is 00:00:10 (10 seconds).
maxRequestEntityAllowed	Optional uint attribute. Specifies the maximum number of bytes that can be in an entity body of a request. If the Content-Length header specifies a larger number, IIS sends a 403 error response. The default value is 4294967295 (unlimited).
uploadReadAheadSize	Optional uint attribute. Specifies the number of bytes that a Web server will read into a buffer and pass to an ISAPI extension or module. This occurs once per client request. The ISAPI extension or module receives any additional data directly from the client. The value must be between 0 and 2147483647. The default value is 49152.

Child Elements

None.

Parent Elements

Element	Description
configuration	Specifies the root element in every configuration file that is used by IIS 7.
system.webServer	Specifies the top-level section group (in ApplicationHost.config) in which this element is defined.

Remarks

Default Configuration

Note Server runtime settings that are contained in a parent configuration file are inherited unless the <clear> element is used in the child configuration file.

The following default <serverRuntime> element is configured in the root ApplicationHost.config file in IIS 7.

<serverRuntime />

Example

The following example configures the Web server to read 65000 bytes into buffer and to pass these buffered bytes to an ISAPI extension or module.

<serverRuntime uploadReadAheadSize="65000" />

Element Information

Configuration locations

Machine.config

ApplicationHost.config

Root application Web.config

Application Web.config

Directory Web.config

Requirements

Microsoft Internet Information Services (IIS) version 7.0