FIX: CPU memory utilization spikes when you parse appInfo elements in XML schemas

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Article ID: 831575 - View products that this article applies to.
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You see a large spike in CPU memory utilization when you use the Microsoft .NET Framework XML schema processor to parse and compile large XML schemas that contain many appInfo elements.


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 Microsoft .NET Framework 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 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  01:46  1.1.4322.968    1,339,392  System.xml.dll   
Note The .NET Framework 1.1 Service Pack 1 will be included with Windows Server 2003 Service Pack 1


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


AppInfo elements are typically used in XML schema documentation. Information that is supplied in the <appinfo> element is intended to be used by an application that consumes the containing schema. The following is a sample schema that reflects the use of an appInfo element in documenting an element definition:
<?xml version="1.0"?>
  <xs:schema xmlns:xs="">
       <xs:element name="State">
                  <xs:documentation>Used to specify a state</xs:documentation>
            <xs:appinfo>NC, TX, and WA are the valid states that can be specified for this element</xs:appinfo>
The parsing of appInfo elements in the implementations of versions 1.0 and 1.1 of the .NET Framework XML schema processor allocated many string and char[] objects that cause the problem that is described in the "Symptoms" section. The parsing implementation has been optimized in this hotfix to reduce the related memory consumption to an acceptable level.


For additional 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


Article ID: 831575 - Last Review: January 17, 2015 - Revision: 2.5
  • Microsoft .NET Framework 1.1
kbnosurvey kbarchive kbhotfixserver kbqfe kbbug kbqfe kbfix KB831575

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