= Fix: IIS error: serverruntime@appconcurrentrequestlimit setting is being exceeded =

**Summary**: Fix the IIS error serverruntime@appconcurrentrequestlimit setting is being exceeded \\
**Date**: 23 September 2022 \\
**Refactor**: 15 December 2024: Checked formatting and added some context. \\
{{tag>iis fix}}

This error happens on IIS when a IIS server is overloaded. By default, the app pool in which the sites live have limited concurrent requets configured. You need to change three settings as shown below. Don't forget to reboot the server afterwards. This was done and tested successful on a Windows Server 2016 with IIS 10.0

== Change App Pool Queue Length ==

Open IIS manager:
* IIS Manager -> <app pool you need to change> -> advanced setting -> queue length
  * Default: 1000
  * New setting: 10000

== appConcurrentRequestLimit ==

Open an administrative command prompt:
* Enter {{{cd %windir%\System32\inetsrv\}}}
* Enter {{{appcmd.exe set config /section:system.webserver/serverRuntime /appConcurrentRequestLimit:15000}}}

This adds the following line to {{{C:\Windows\System32\inetsrv\config\applicationHost.config}}}:
* {{{<serverRuntime appConcurrentRequestLimit="15000" />}}}
* Default is 5000

== requestQueueLimit ==

* Open notepad als admin
  * Open file {{{C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config}}}
    * Note that the framework version can change
  * Replace {{{<processModel autoConfig="true"/>}}}
  * With {{{<processModel enable="true" requestQueueLimit="15000" />}}}

Reboot the server.