Application Pool Defaults <applicationPoolDefaults>

Overview

The <applicationPoolDefaults> collection of the <applicationPools> collection configures default values for all application pools on a Web server.

Note: Any default values that are not explicitly defined in the <applicationPoolDefaults> collection will still inherit the default values in the IIS 7 and later schema, and individual application pool settings override any default values.

Compatibility

Version Notes
IIS 8.5 The <applicationInitialization> element was not modified in IIS 8.5.
IIS 8.0 Another value ("v4.0") was added to the managedRuntimeVersion attribute in IIS 8.0, and its default value was changed to "" instead of "v2.0".
IIS 7.5 The <applicationPoolDefaults> element was not modified in IIS 7.5.
IIS 7.0 The <applicationPoolDefaults> element was introduced in IIS 7.0.
IIS 6.0 The <applicationPoolDefaults> element replaces portions of the IIS 6.0 IIsApplicationPools metabase property.

Setup

The <applicationPools> collection is included in the default installation of IIS 7 and later.

How To

How to set up application pool defaults

  1. Open Internet Information Services (IIS) Manager:
    • If you are using Windows Server 2012 or Windows Server 2012 R2:
      • On the taskbar, click Server Manager, click Tools, and then click Internet Information Services (IIS) Manager.
    • If you are using Windows 8 or Windows 8.1:
      • Hold down the Windows key, press the letter X, and then click Control Panel.
      • Click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.
    • If you are using Windows Server 2008 or Windows Server 2008 R2:
      • On the taskbar, click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
    • If you are using Windows Vista or Windows 7:
      • On the taskbar, click Start, and then click Control Panel.
      • Double-click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.
  2. In the Connections pane, expand the server name, and then click Application Pools.
  3. In the Actions pane, click Set Application Pool Defaults...
  4. On the Application Pool Defaults dialog box, specify your desired options.
  5. When you have finished specifying your settings, click OK.

Configuration

Attributes

Attribute Description
autoStart Optional Boolean attribute.

When true, indicates to the World Wide Web Publishing Service (W3SVC) that the application pool should be automatically started when it is created or when IIS is started.

The default value is true.
CLRConfigFile Optional string value.

Specifies the .NET configuration file for the application pool.

Note: This attribute was added in IIS 7.5.

There is no default value.
enable32BitAppOnWin64 Optional Boolean attribute.

When true, enables a 32-bit application to run on a computer that runs a 64-bit version of Windows.

The default value is false.
managedPipelineMode Optional enum attribute.

Specifies the request-processing mode that is used to process requests for managed content.

The managedPipelineMode attribute can be one of the following possible values; the default is Integrated.
Value Description
Classic Specifies that the application pool use separate IIS and ASP.NET request-processing pipelines, which works with ASP.NET 1.1 applications, and ASP.NET 2.0 applications that do not work in Integrated mode.

The numeric value is 1.
Integrated Specifies that the application pool use the integrated IIS and ASP.NET request-processing pipeline, which works with only ASP.NET 2.0 or later applications.

The numeric value is 0.
managedRuntimeLoader Optional string attribute.

Specifies the managed loader to use for pre-loading the the application pool.

Note: This attribute was added in IIS 7.5.

The default value is webengine4.dll.
managedRuntimeVersion Optional string attribute.

Specifies the .NET Framework version to be used by the application pool.

The managedRuntimeVersion attribute can be one of the following possible values; the default value is "".
Value Description
v1.1 Specifies that the application pool use the .NET Framework version 1.1.
v2.0 Specifies that the application pool use the .NET Framework version 2.0.
v4.0 Specifies that the application pool use the .NET Framework version 4.0.
name Required string attribute.

Specifies a unique name for an application pool on the server.
queueLength Optional uint attribute.

Indicates to HTTP.sys how many requests to queue for an application pool before rejecting future requests.

When the value set for this property is exceeded, IIS rejects subsequent requests with a 503 error. If the loadBalancerCapabilities setting is true, the connection is closed instead of rejecting requests with a 503. For more information about loadBalancerCapabilities, see Failure Settings for an Application Pool.

The default value is 1000.
startMode Optional enum value.

Specifies the startup type for the application pool.

Note: This attribute was added in IIS 7.5.

The startMode attribute can be one of the following possible values; the default value is OnDemand.
Value Description
AlwaysRunning Specifies that the Windows Process Activation Service (WAS) will always start the application pool. This behavior allows an application to load the operating environment before any serving any HTTP requests, which reduces the start-up processing for initial HTTP requests for the application.

The numeric value is 1.
OnDemand Specifies that the Windows Process Activation Service (WAS) will start the application pool when an HTTP request is made for an application that is hosted in the application pool. This behavior resembles the WAS behavior in previous versions of IIS.

The numeric value is 0.

Child Elements

Element Description
cpu Configures CPU affinity and CPU actions.
failure Configures actions to take when an application pool fails.
processModel Configures process management attributes for an application pool.
recycling Configures application pool recycling.

Configuration Sample

The following configuration sample specifies the default identity for all application pools to be the built-in application pool identity, and specifies 200 as the default number of requests after which application pools are recycled.

<applicationPools>
   <add name="DefaultAppPool" />
   <applicationPoolDefaults>
      <processModel identityType="ApplicationPoolIdentity" />
      <recycling>
         <periodicRestart requests="200" />
      </recycling>
   </applicationPoolDefaults>
</applicationPools>

Sample Code

The following examples configure the application pools to start automatically, to use version 2.0 of the .NET environment, and to use the integrated pipeline by default.

AppCmd.exe

appcmd.exe set config -section:system.applicationHost/applicationPools /applicationPoolDefaults.autoStart:"True" /commit:apphost

appcmd.exe set config -section:system.applicationHost/applicationPools /applicationPoolDefaults.managedRuntimeVersion:"v2.0" /commit:apphost

appcmd.exe set config -section:system.applicationHost/applicationPools /applicationPoolDefaults.managedPipelineMode:"Integrated" /commit:apphost

Note: You must be sure to set the commit parameter to apphost when you use AppCmd.exe to configure these settings. This commits the configuration settings to the appropriate location section in the ApplicationHost.config file.

C#

using System;
using System.Text;
using Microsoft.Web.Administration;

internal static class Sample {

   private static void Main() {

      using(ServerManager serverManager = new ServerManager()) { 
         Configuration config = serverManager.GetApplicationHostConfiguration();

         ConfigurationSection applicationPoolsSection = config.GetSection("system.applicationHost/applicationPools");

         ConfigurationElement applicationPoolDefaultsElement = applicationPoolsSection.GetChildElement("applicationPoolDefaults");
         applicationPoolDefaultsElement["autoStart"] = true;
         applicationPoolDefaultsElement["managedRuntimeVersion"] = @"v2.0";
         applicationPoolDefaultsElement["managedPipelineMode"] = @"Integrated";

         serverManager.CommitChanges();
      }
   }
}

VB.NET

Imports System
Imports System.Text
Imports Microsoft.Web.Administration

Class Sample
   Shared Sub Main()
      Dim serverManager As ServerManager = New ServerManager
      Dim config As Configuration = serverManager.GetApplicationHostConfiguration
      Dim applicationPoolsSection As ConfigurationSection = config.GetSection("system.applicationHost/applicationPools")
      Dim applicationPoolDefaultsElement As ConfigurationElement = applicationPoolsSection.GetChildElement("applicationPoolDefaults")
      applicationPoolDefaultsElement("autoStart") = True
      applicationPoolDefaultsElement("managedRuntimeVersion") = "v2.0"
      applicationPoolDefaultsElement("managedPipelineMode") = "Integrated"
      serverManager.CommitChanges()
   End Sub
End Class

JavaScript

var adminManager = new ActiveXObject('Microsoft.ApplicationHost.WritableAdminManager');
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST";

var applicationPoolsSection = adminManager.GetAdminSection("system.applicationHost/applicationPools", "MACHINE/WEBROOT/APPHOST");
var applicationPoolDefaultsElement = applicationPoolsSection.ChildElements.Item("applicationPoolDefaults");
applicationPoolDefaultsElement.Properties.Item("autoStart").Value = true;
applicationPoolDefaultsElement.Properties.Item("managedRuntimeVersion").Value = "v2.0";
applicationPoolDefaultsElement.Properties.Item("managedPipelineMode").Value = "Integrated";

adminManager.CommitChanges();

VBScript

Set adminManager = WScript.CreateObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"

Set applicationPoolsSection = adminManager.GetAdminSection("system.applicationHost/applicationPools", "MACHINE/WEBROOT/APPHOST")
Set applicationPoolDefaultsElement = applicationPoolsSection.ChildElements.Item("applicationPoolDefaults")
applicationPoolDefaultsElement.Properties.Item("autoStart").Value = True
applicationPoolDefaultsElement.Properties.Item("managedRuntimeVersion").Value = "v2.0"
applicationPoolDefaultsElement.Properties.Item("managedPipelineMode").Value = "Integrated"

adminManager.CommitChanges()
Deprecated Elements