FIX: It takes a long time to add a new website in a shared hosting environment on a web server that is running IIS 7.0 or IIS 7.5

Consider the following scenario. In a shared hosting environment, you host many websites on a webserver that is running Internet Information Services (IIS) 7.0 or IIS 7.5. For example, you host one thousand websites on the webserver. Additionally, you create many application pools for these websites to run in. In this scenario, it takes several minutes to add a new website to the web server.

This issue occurs because the way that IIS maintains isolated configuration files causes performance issues in a shared hosting environment.

When a website in an application pool first receives a request from a client, the Windows Process Activation Service (WAS) creates an isolated configuration file. The WAS does this by filtering the configuration data for the application pool that is in the ApplicationHost.config file. By default, the isolated configuration file is located in the following directory:
In a shared hosting environment, many isolated configuration files are located in the same directory. When a new website is added to the web server, the ApplicationHost.config file is updated. This triggers an update of all the isolated configuration files. Because all the files are located in one directory, this process takes a long time.

Note After you apply the hotfix, the isolated configuration files are located in different folders instead of being located in the same folder.

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites

You must have IIS 7.0 or IIS 7.5 installed to apply this hotfix. Additionally, your computer must be running one of the following operating systems:

• Windows Vista SP2
• Windows Server 2008 SP2
• Windows 7
• Windows Server 2008 R2

Restart requirement

You must stop and then restart the WAS after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

File information for Windows Vista SP2 and for Windows Server 2008 SP2

For all supported x86-based versions of Windows Vista SP2 and of Windows Server 2008 SP2

For all supported x64-based versions of Windows Vista SP2 and of Windows Server 2008 SP2

For all supported IA-64-based versions of Windows Server 2008 SP2

File information for Windows 7 and for Windows Server 2008 R2

For all supported x86-based versions of Windows 7 and of Windows Server 2008 R2

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

For all supported IA-64-based versions of Windows 7 and of Windows Server 2008 R2

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: