Caching Service on www.upenn.edu (effective March 25, 2004)
Transition Issues for Web Providers

ISC Networking and Telecommunications has contracted with Akamai, http://www.akamai.com, to provide a web caching service for all pages housed on www.upenn.edu. While the current www.upenn.edu can easily handle normal daily requests for web pages, there have been instances throughout the year when major events in Penn's academic cycle have placed greater demands on www.upenn.edu for short periods of time. Rather than upgrading the server to accommodate these temporary periods of high volume, we have opted to subscribe to Akamai's caching service.

Beginning on March 25, 2004, all pages on www.upenn.edu will be served from the cache being stored on one of the Akamai EdgeSuite servers. When a user requests a page from www.upenn.edu, instead of being sent to www.upenn.edu to get the page, the user will be redirected to one of the many Akamai caching servers to get a copy of the page. This method insures better response time for the user, more reliability and less resource consumption on our own server.

Information about this service is detailed on the Caching Service on www.upenn.edu page. In addition, this page has been created to document issues that surface during the transition period. Check back regularly between now and March 25 for updates.

Change FTP Client Settings

www.upenn.edu providers use FTP to upload data to the server. Since the hostname www.upenn.edu now points to the Akamai servers, you can no longer FTP to www.upenn.edu. You must change the configuration for your FTP client to point to origin.www.upenn.edu.

Overriding the Cache for Dynamic Pages

In this discussion of our caching service, dynamic content is information in a web page that is updated on a regular basis more often than once in 5 minutes. In order for your pages not to be cached, providers need to put code in place to override the cache.

See the Caching Service on www.upenn.edu page for instructions about how to override the default cache, if you require it.

Content providers needing to override the cache can implement the settings prior to the launch of the caching service on March 25th without detriment to your current pages. To confirm that overrides will work once caching commences on the 25th, providers can get a preview of their pages now by using http://test-www.upenn.edu/.

If the URL of one of your pages is usually http://www.upenn.edu/mysite/index.htm point your browser to:

http://test-www.upenn.edu/mysite/index.html

You will be looking at a cached version of your page. Please note that you only need to use this different hostname during the testing period prior to March 25, 2004.

Changes to Altavista Search indexes

Although you do not need to change most links in order to take advantage of the caching, the one exception to this rule is linking to the Altavista search indexes. See the Caching Service on www.upenn.edu page for more details about how to modify your searches.

"Invalid URL" Error Due to Domain Names which are Not Fully Qualified

If you or your end users get the error, "Invalid URL", when requesting a page from www.upenn.edu, your browser may have been configured so that you could have requested a page from www.upenn.edu without having to fully qualify the domain name. Instead of typing http://www.upenn.edu/almanac/ you may be accustomed to typing http://www/almanac/.

Since www.upenn.edu now redirects to the Akamai caching service gateway and that gateway must know the actual hostname of the server that is trying to be reached, users must specify the full URL when requesting www.upenn.edu pages with your browser.

You may also receive this error message if you are using a very old browser that doesn't support the newer HTTP/1.1 protocol.

Note for Developers Who are Using the Apache/Websec Module

If you are using the Apache/Websec module to restrict access to your web pages on www.upenn.edu which requires that a user authenticate first with his/her PennKey before being able to view your pages, you must turn off caching and IP-checking for your pages.

See the Caching Service on www.upenn.edu page for more details.