FIX: Response That Contains the Cache-Control: s-maxage=0 Header Does Not Expire Immediately (824246)


The information in this article applies to:

  • Microsoft Internet Security and Acceleration Server 2000
  • Microsoft Internet Security and Acceleration Server 2000 SP1

SYMPTOMS

If you use Internet Security and Acceleration (ISA) Server 2000 in either a Web publishing scenario or a Web proxy scenario, ISA Server may not immediately expire a response that contains the Cache-Control: s-maxage=0 header. This header is used to tell a proxy server not to use an entry after it is delivered to the requesting client unless it first revalidates the entry with the origin server. A value of 0 means that the cached response should expire immediately.

CAUSE

This problem occurs because ISA Server does not immediately expire the content. ISA Server waits for the current time to be greater than the request time in whole seconds. ISA Server incorrectly returns cached content for new requests that are made to the same resource within the same second without first revalidating the entry with the origin server.

RESOLUTION

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 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

You must install ISA Server 2000 Service Pack 1 (SP1) before you install the following hotfix. For additional information about how to obtain the latest ISA Server service pack, click the following article number to view the article in the Microsoft Knowledge Base:

313139 How to Obtain the Latest Internet Security and Acceleration Server 2000 Service Pack

File Information

The English version of this fix 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
   --------------------------------------------------------------
   10-Jul-2003  18:42  3.0.1200.281      178,448  Mspadmin.exe     
   10-Jul-2003  18:41  3.0.1200.281      103,184  Msphlpr.dll      
   10-Jul-2003  18:41  3.0.1200.281      392,464  W3proxy.exe      
   10-Jul-2003  18:41  3.0.1200.281      299,280  Wspsrv.exe
Note This fix also applies to the French, German, Spanish, and Japanese versions of ISA Server.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

For additional information about Cache-Control headers, see section 14.9 in the Hypertext Transfer Protocol -- HTTP/1.1 RFC 2616.
Modification Type:MinorLast Reviewed:10/26/2005
Keywords:kbHotfixServer kbQFE kbHotfixServer kbQFE kbBug kbISAServ2000preSP2fix KB824246 kbAudDeveloper
©2004 Microsoft Corporation. All rights reserved.