FIX: Csc.exe runs unexpectedly when you try to access Web services by using ASP.NET

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Article ID: 831259 - View products that this article applies to.
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If your Microsoft ASP.NET Web application makes calls to XML Web services, you may notice in Task Manager that an instance of Csc.exe runs briefly the first time that the application calls each XML Web service. This is typical behavior.

However, depending on the memory usage of the application and the number of different Web services that the application calls, Csc.exe may also run again after each Web service and each ASP.NET page has been called one time. In extreme cases, this behavior can cause poor performance of the application.


A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next .NET Framework 1.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product 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.

The English version of this hotfix has the file attributes (or later) 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
   11-Nov-2003  19:44                    4,169  Aspnet_perf.h
   11-Nov-2003  19:52                  513,302  Iaspnet_perf.ini
   11-Nov-2003  19:52                  510,714  Aspnet_perf2.ini
   11-Nov-2003  19:52  1.0.3705.470     28,672  Aspnet_wp.exe
   11-Nov-2003  19:52  1.0.3705.470     24,576  Aspnet_regiis.exe
   11-Nov-2003  19:52  1.0.3705.470    200,704  Aspnet_isapi.dll
   11-Nov-2003  19:06  1.0.3705.470     69,632  CORPerfMonExt.dll
   08-Sep-2003  17:28                   17,807  InstallSqlStateTemplate.sql
   17-Jun-2003  14:43                   16,597  InstallPersistSqlState.sql
   17-Jun-2003  14:43                   17,331  InstallSqlState.sql
   11-Nov-2003  19:06  1.0.3705.470  2,269,184  Mscorwks.dll
   11-Nov-2003  19:05  1.0.3705.470  2,273,280  Mscorsvr.dll
   11-Nov-2003  19:04  1.0.3705.470    303,104  Mscorjit.dll
   12-Nov-2003  09:21  1.0.3705.470  1,953,792  Mscorlib.dll
   11-Nov-2003  18:58                   10,284  Mscorlib.ldo
   11-Nov-2003  19:48  1.0.3705.470     20,480  PerfCounter.dll
   29-Jul-2003  17:04                    8,728  SmartNav.js
   22-Aug-2002  19:23                       15  SmartNav.htm
   12-Nov-2003  09:20  1.0.3705.470  1,196,032  System.Web.dll
   12-Nov-2003  09:18  1.0.3705.470    507,904  System.Web.Services.dll
   12-Nov-2003  09:21  1.0.3705.470  1,994,752  System.Windows.Forms.dll
   11-Nov-2003  19:58                   16,700  System.Windows.Forms.ldo
   11-Nov-2003  19:53  1.0.3705.470     57,344  System.Windows.Forms.tlb
   12-Nov-2003  09:20  1.0.3705.470  1,302,528  System.XML.dll
   12-Nov-2003  09:20  1.0.3705.470  1,179,648  System.Data.dll
   12-Nov-2003  09:21  1.0.3705.470  1,695,744  System.Design.dll
   12-Nov-2003  09:19  1.0.3705.470  1,175,552  System.dll
   12-Nov-2003  09:18  1.0.3705.470    241,664  System.Messaging.dll
   12-Nov-2003  09:18  1.0.3705.470    311,296  System.Runtime.Remoting.dll
   12-Nov-2003  09:17  1.0.3705.470    131,072  System.Runtime.Serialization.Formatters.Soap.dll
   12-Nov-2003  09:15  1.0.3705.470     32,768  TlbImp.exe
   08-Sep-2003  17:28                    2,119  UninstallSqlStateTemplate.sql
   17-Jun-2003  14:43                    1,419  UninstallPersistSqlState.sql
   12-Nov-2003  09:16  1.0.3705.470     65,536  Wsdl.exe


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

This problem was corrected in the Microsoft .NET Framework 1.1.


ASP.NET and Web services in the Microsoft .NET Framework use dynamic compilation of code. ASP.NET uses this technique to compile .aspx or .asmx pages that have inline code in them. By default, the resulting assembly is cached in the Temporary ASP.NET Files folder. To compile these pages, the .NET Framework runs the Csc.exe file, the Vbc.exe file, or another command line compiler, depending on the .NET-compatible programming language that is used in the page.

When an application calls Web services, the .NET Framework automatically generates and compiles client proxy classes. The .NET Framework generates these classes in C# and then runs the Csc.exe compiler to compile these classes. The resulting assemblies are cached in memory in the ASP.NET cache.

Before you apply this hotfix, these generated assemblies may be displaced from the cache because of memory pressure. Therefore, the .NET Framework must recompile these assemblies again the next time that the application requires them.

For additional information about the terminology that is used to describe Microsoft product updates, 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


Article ID: 831259 - Last Review: October 25, 2005 - Revision: 1.4
  • Microsoft .NET Framework 1.0
kbbug kbfix kbqfe kbnetframe100presp3fix kbhotfixserver KB831259

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