Microsoft KB Archive/894484

= FIX: You experience high memory usage in the W3wp.exe file on a computer that is running Windows Server 2003 and that has Internet Information Services (IIS) 6.0 installed =

Article ID: 894484

Article Last Modified on 12/8/2005

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APPLIES TO


 * Microsoft Internet Information Services 6.0

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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



SYMPTOMS
You experience high memory usage in the W3wp.exe file on a computer that is running Microsoft Windows Server 2003 and that has Microsoft Internet Information Services (IIS) 6.0 installed.

This problem occurs during the transfer of a large file to a client computer when you use an Active Server Pages (ASP) response write method. An example of an ASP response write method is the Response.BinaryWrite method. The memory usage in the W3wp.exe file may be as high as the size of the file that is being transferred. Typically, this problem occurs when the client computer uses a slow connection link.



Hotfix information
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, we recommend that you wait for the next Windows Server 2003 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:

http://support.microsoft.com/contactus/?ws=support

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
No prerequisites are required.

Restart requirement
If the Asp.dll file is being used when you apply this hotfix, you must restart the computer after you apply this hotfix.

If you do not want to restart the computer after you apply this hotfix, stop all IIS services before you apply this hotfix. To stop all IIS services, type Iisreset /stop at a command prompt, and then press ENTER.

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 tool in Control Panel.

Windows Server 2003, Itanium architecture
  Date         Time   Version       Size     File name  Platform ---  25-Jun-2005  02:48  6.0.3790.357  985,600  Asp.dll    IA-64

Windows Server 2003 Service Pack 1, Itanium architecture
  Date         Time   Version        Size       File name  Platform -  25-Jun-2005  02:48  6.0.3790.2474  1,063,424  Asp.dll    IA-64 25-Jun-2005 02:48  6.0.3790.2474    379,392  Wasp.dll   x86

Windows Server 2003 Service Pack 1, x64
  Date         Time   Version        Size     File name --  25-Jun-2005  02:48  6.0.3790.2474  611,328  Asp.dll 25-Jun-2005 02:48  6.0.3790.2474  379,392  Wasp.dll

Windows Server 2003, x86
  Date         Time   Version       Size     File name -  25-Jun-2005  02:16  6.0.3790.357  381,440  Asp.dll

Windows Server 2003 Service Pack 1, x86
  Date         Time   Version        Size     File name --  25-Jun-2005  02:26  6.0.3790.2474  379,392  Asp.dll



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
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.

In IIS 6.0, an ASP Web application uses asynchronous writes to the Http.sys file to transfer data to a client computer. If the client computer uses a slow connection and slowly retrieves the requested data, the data will be queued in memory on the Web server.

After you apply this hotfix, you can configure the number of bytes that can be queued in memory. If the limit that you configure is reached, the file transfer is paused until the client computer retrieves enough data so that the amount of queued data is lower than the configured limit.

To limit the amount of data that can be queued in the W3wp.exe file, follow these steps:  Install the hotfix that is described in this article. Click Start, click Run, type regedit, and then click OK. Locate and then click the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ASP\Parameters

</li> If VectorSendThrottleLimit exists, go to step 7. If VectorSendThrottleLimit does not exist, go to step 5.</li> On the Edit menu, point to New, and then click DWORD Value.</li> Type VectorSendThrottleLimit, and then press ENTER.</li> In the right pane, right-click VectorSendThrottleLimit, and then click Modify.</li> In the Value data box, type the value that you want, and then click OK.

Notes <ul> By default, this feature is disabled, and the registry value does not exist. When this feature is disabled, the value for this subkey is 0.</li> Because this setting may also limit the throughput of downloads that use the Response.BinaryRead method, ASP pages may not appear as expected if you set the value for this subkey too low. For example, if you set the value for this subkey to 100, any ASP page that transfers more than 100 bytes will not appear as expected.</li></ul> </li></ol>

Keywords: kbfix kbbug kbqfe kbmsccsearch kbpubtypekc KB894484

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