WEB CACHING

• Browser Caching
  Your web browser caches web pages in order to quickly serve them to you without revisiting sites. If you are having trouble refreshing cached pages, read refreshing your web browser's cache.
• Proxy Caching
  OlympusNet uses a caching server, called a "proxy" server, for serving web pages. When you click on a web page, your request goes first to the caching server. If the server already has a copy of the page, it sends it to you without having to fetch it from the Internet, delivering the page quickly and reducing the load on our high-speed circuits. If the caching server doesn't already have the page, it fetches it across the high-speed circuits, sends it to you, and stores a copy for the next access. Our caching server does not cache sites stored on the OlympusNet network. In other words, we don't cache our own web pages.

  Most developers of web pages which should not be cached have already done what is needed to avoid having those pages cached. If you aren't sure you are getting the most up-to-date version of a page, you can force our caching server to query the site the page comes from (see refreshing your web browser's cache).

  For developers, web caching is both helpful and problematic. It does mean faster downloads and savings in bandwith but at the same time it can mean that you are unable to view changes to pages as they are made, and that pages with frequent updates may appear stale to your site visitors. It is a good idea for developers to learn how to configure their sites to take advantage of caching and to make them as cacheable as possible. This is done using the "Expires" and "Cache-Control" HTTP headers. To learn more about caching and using these headers, read this excellent Caching Tutorial for Web Authors and Webmasters. (Note: the OlympusNet Apache web server does have both the "mod_headers" and "mod_expires" modules enabled.)