Solved

Changing "Cache-Control: Private" setting in IIS 6

Posted on 2008-09-30
4
7,166 Views
Last Modified: 2013-12-02
Hello,

We are attempting to change the setting for the "Cache-Control" value from the default of "Private" to a new setting with an expiration time.

We have tried using the HTTP HEADER "Add" function in IIS but it does not seem authoritative when using CURL on the URL.

We have also used the following script to change in the metabase (and then hard reset IIS)

Microsoft Windows [Version 5.2.3790]
(C) Copyright 1985-2003 Microsoft Corp.

C:\Documents and Settings\glg.admin>Cd C:\inetpub\adminscripts\

C:\Inetpub\AdminScripts>CSCRIPT adsutil.vbs set w3svc/SITENUMBER/root/includes/c
achecontrolcustom "public"
Microsoft (R) Windows Script Host Version 5.6
Copyright (C) Microsoft Corporation 1996-2001. All rights reserved.

cachecontrolcustom              : (STRING) "public"

C:\Inetpub\AdminScripts>


While the metabase file shows the cache-control as public. Using Curl on the URL still shows "Cache-Control: Private"

Our CDN can not long term cache the content without this setting being changed. Microsoft only points out the method above (from the Dos prompt) for changing the cache control header. Are we to resort to doing this code side? Is there no other way to change it server wide?

Our Curl statement ends up looking like this:
Microsoft Windows [Version 6.0.6000]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

P:\>cd C:\curl

P:\>c:

C:\curl>curl -I http://wwww.domainname.com/includes/header.aspx
HTTP/1.1 200 OK
Date: Tue, 30 Sep 2008 21:54:36 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Cache-Control: max-age=86000, no-check
X-AspNet-Version: 2.0.50727
Cache-Control: private
Content-Type: text/html; charset=utf-8
Content-Length: 3080


Our network setup is 2 web servers behind a zeus load balancer which are then serving as origin for a content delivery network. The content delivery network has shielding enabled but cannot hold the contnet long enough to be effective. Long term result - a 503 error in accessing content from origin will drop both servers from the load balancing pool and show errors to the user. Note that the CDN Curl statement below shows the cache dropping the more liberal of the two Cache-Control settings.

Microsoft Windows [Version 6.0.6000]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.


C:\curl> curl -I http://cache.domainname.com/includes/header.aspx
HTTP/1.1 200 OK
Date: Tue, 30 Sep 2008 21:59:18 GMT
Server: PWS/1.3.26
Transfer-Encoding: chunked
X-Px: ms sfo-agg-n35 (sfo-agg-n50), ms sfo-agg-n50 (jfk-agg-x2), ms jfk-agg-x2 (
origin)
Content-Type: text/html; charset=utf-8
Cache-Control: private
Connection: keep-alive


Thanks in advance!

Chris
0
Comment
Question by:garriganlyman
  • 2
  • 2
4 Comments
 
LVL 34

Expert Comment

by:Dave_Dietz
Comment Utility
What happens if you request non-dynamic content such as an HTML page?

I believe the Cache-control header is being set by the ASP.Net runtime and since it is set IIS will not overwrite it.

Dave Dietz
0
 

Author Comment

by:garriganlyman
Comment Utility
That's an excellent question. When running curl on an html file the cache-control header value is correct. If the value is being set by the ASP.NET runtime - does that mean that it needs to be changed on the fly in the code?
0
 
LVL 34

Accepted Solution

by:
Dave_Dietz earned 500 total points
Comment Utility
Yeppers.  :-)

Try taking a look at this:

HttpCachePolicy Class
http://msdn.microsoft.com/en-us/library/system.web.httpcachepolicy(VS.71).aspx

Should give you the answers you need.  :-)

Dave Dietz
0
 

Author Closing Comment

by:garriganlyman
Comment Utility
This solution is now working in our staging environment - THANKS DAVE!
0

Featured Post

6 Surprising Benefits of Threat Intelligence

All sorts of threat intelligence is available on the web. Intelligence you can learn from, and use to anticipate and prepare for future attacks.

Join & Write a Comment

Suggested Solutions

User art_snob (http://www.experts-exchange.com/M_6114203.html) encountered strange behavior of Android Web browser on his Mobile Web site. It took a while to find the true cause. It happens so, that the Android Web browser (at least up to OS ver. 2.…
One of the typical problems I have experienced is when you have to move a web server from one hosting site to another. You normally prepare all on the new host, transfer the site, change DNS and cross your fingers hoping all will be ok on new server…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…

743 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now