Overview

When first introduced to Web content caching, many network administrators assume that the object cache on an Excelerator appliance is basically the same as a browser's cache, which all users access when they click the Back button. The logical extension from this assumption is the fear that Excelerator will serve stale content that doesn't accurately reflect the fresh content on the origin Web server.

Actually, most time-sensitive Web content is flagged by Webmasters in such a way that it cannot become stale unless a caching system ignores the Webmaster's settings. And in fact, the Excelerator appliance honors all flags that affect cache freshness, including Time to Expire, Don't Cache, and Must Revalidate directives.

In addition, the Excelerator appliance can be fine-tuned for cache freshness in the following ways:

• Accelerated checking of objects that have longer than desirable Time to Expire headers
• Delayed checking of objects that have shorter than desirable Time to Expire headers
• Checking for freshness of objects that do not include Time to Expire headers

For more information on configuring Excelerator for cache freshness, see Managing Cache Freshness and Cache Freshness Dialog Box.