SYMPTOMS
When you turn on HTTP compression for dynamic content in Web
sites in Microsoft Internet Information Services (IIS) 6.0, you may experience
unexpected behavior when you browse Web sites that use an Internet Server API
(ISAPI) filter. This problem occurs if the following conditions are true:
- The ISAPI filter registers for the SF_NOTIFY_SEND_RAW_DATA notification and optionally registers for the SF_NOTIFY_SEND_RESPONSE notification.
- The ISAPI Filter buffers the response in the SF_NOTIFY_SEND_RAW_DATA notification and then reinterprets the buffered response to
determine whether the response is chunked.
The symptoms that you experience include one or more of the
following:
CAUSE
This problem occurs if the following conditions are true, in
the order that they are presented:
- IIS detects that dynamic compression applies to the
response data and then adds the following header fields, as needed:
- Content-Encoding
- Vary
- Transfer-Encoding
- IIS notifies the SF_NOTIFY_SEND_RESPONSE filters. The SF_NOTIFY_SEND_RESPONSE filters detect the headers that IIS added.
- IIS starts to send the response and calls the SF_NOTIFY_SEND_RAW_DATA filters.
- The response is compressed, is chunked, and then is sent to
the client.
IIS adds compression headers to the response in step 1. However,
the data is not actually modified until step 4. Therefore, when the filter
tries to reinterpret the response, filter events that occur between step 1 and
step 4 notice that inconsistencies exist between the headers and the body of
the response. The headers indicate that the response contains compressed and
chunked data. However, the body of the response may or may not be compressed or
chunked.
RESOLUTION
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:
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
Stop IIS before you apply this hotfix, and then restart IIS after
you apply this hotfix.
Note To stop IIS, click
Start, click
Run, type
net stop w3svc in the
Open box, and then click
OK.
To
start IIS after you stop it, click
Start, click
Run, type
net start w3svc in the
Open box, and then click
OK.
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
Date Time Version Size File name
-----------------------------------------------------
27-Jul-2004 17:41 6.0.3790.196 342,016 W3core.dll
Windows Server 2003, 64-Bit Edition
Date Time Version Size File name
------------------------------------------------------------
27-Jul-2004 17:41 6.0.3790.196 950,784 W3core.dll IA-64