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FIX: When I/O thread processes a slow request, completions on named pipes between Inetinfo.exe and Aspnet_wp.exe are blocked in the .NET Framework 1.0

View products that this article applies to.

Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 ( ) Description of the Microsoft Windows registry

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You may notice that a Web application exhibits the following issues:
  • Long running, CPU intensive operations block other requests from executing. This behavior causes requests to queue.
  • Requests appear to be "stuck" in the request queue.

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Requests that run on I/O threads that consume 100 percent of the available CPU capacity cause the completions on the named pipes between the Inetinfo.exe process and the Aspnet_wp.exe process to be blocked. These completions remain blocked until CPU capacity is available. This behavior causes incoming requests to be blocked.

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To avoid these issues, ALL requests now run on Worker threads. This scenario frees the I/O threads to continue to process completions.

Note This scenario is a significant change in behavior. Because of this change, you may have to configure, test, and stress the following configuration settings:
  • maxIOThreads in the <processModel> section
  • maxWorkerThreads in the <processModel> section
  • minFreeThreads in the <httpRuntime> section

How to obtain the hotfix

This issue is fixed in the June 2003 ASP.NET Hotfix Package 1.1. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
821156� ASP.NET 1.1 June 2003 Hotfix Rollup Package
Note When you request this hotfix, you receive the hotfix rollup package. You cannot obtain this hotfix individually. You must apply the hotfix rollup package.

If you upgrade to the .NET Framework version 1.1

If you apply the hotfix rollup package that is described in Microsoft Knowledge Base article 821156, and then you upgrade to Microsoft ASP.NET that is included with the .NET Framework 1.1, you must apply the hotfix rollup package again.

Additionally, if you experience the issues that are mentioned in the "Symptoms" section after you upgrade to the .NET Framework 1.1, you must apply the hotfix rollup package again.

Note If you have the .NET Framework 1.1 Service Pack 1 (SP1) installed, you must create a registry key to enable this hotfix.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

Create the following registry key to enable this hotfix on the .NET Framework 1.1 SP1:

Value name: UseWorkerThreadsOnIIS5
Data type: REG_DWORD
Value data: 1

Hotfix 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 tool in Control Panel.
   Date         Time   Version       Size       File name
   01-May-2003  12:46  1.0.3705.419    196,608  Aspnet_isapi.dll
   01-May-2003  12:46                    4,169  Aspnet_perf.h
   01-May-2003  12:46                   20,468  Aspnet_perf.ini
   01-May-2003  12:46                   20,342  Aspnet_perf2.ini
   01-May-2003  12:46  1.0.3705.419     24,576  Aspnet_regiis.exe
   01-May-2003  12:46  1.0.3705.419     28,672  Aspnet_wp.exe
   01-May-2003  12:46  1.0.3705.419     69,632  Corperfmonext.dll
   01-May-2003  12:46  1.0.3705.419    303,104  Mscorjit.dll
   01-May-2003  12:46  1.0.3705.419  1,953,792  Mscorlib.dll
   01-May-2003  12:46                   10,284  Mscorlib.ldo
   01-May-2003  12:46  1.0.3705.419  2,269,184  Mscorsvr.dll
   01-May-2003  12:46  1.0.3705.419  2,269,184  Mscorwks.dll
   01-May-2003  12:46                       15  Smartnav.htm
   01-May-2003  12:46                    8,728  Smartnav.js
   01-May-2003  12:46  1.0.3705.419  1,191,936  System.web.dll

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

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More information

For more information, click the following article number to view the article in the Microsoft Knowledge Base:
824684� Description of the standard terminology that is used to describe Microsoft software updates

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Keywords: KB816829, kbbug, kbfix, kbnetframe100presp3fix, kbqfe, kbhotfixserver

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Article Info
Article ID : 816829
Revision : 9
Created on : 9/27/2005
Published on : 9/27/2005
Exists online : False
Views : 490