Understanding Web Server Log FIles

The Cached Hit and Other Web Server Return Codes

What the heck is a “cached hit” and how is this different than a regular hit?

Well, they aren’t really different. Both of them constitute a "hit" and "page view." So, why are they counted differently? Because programers are thorough. A regular hit is activity that must be served up by your server: this takes up more bandwidth than a cached hit.

So, what is a cache?
A cache is a temporary storage location for regularly or recently accessed files. This is done in an effort to improve performance. There are memory, bios, browser and proxy caches. For our purposes, they can exist in one of two places: in your browser, or on a proxy server.

The browser cache
Say you go to your web site at www.yourdomain.com, and then click the back button on your browser to come back to this page. Chances are that you will return to this page much faster than when you first got here. This is because a copy of this page and all the graphics on this page were stored to your browser cache so that you wouldn't have to wait for the web server to serve up the same page again.

The amount of time that a page will stay in your cache depends on your browser settings. Usually they are set to some default size. Once that byte size is exceeded, the browser begins to empty the older files from the cache.

The proxy cache
Many Intranets these days are starting to realize that bandwidth = $$$. One way that a company can save money, which has the added benefit of improving browsing performance for their employees is to install a proxy server. This proxy server also has a cache. Most have very huge caches which store recently or often requested pages. This works exactly the same way as a browser cache but can hold gigs of data, and the data that is stored can be determined by the administrator. Often times the entire Intranet structure of businesses is cached in proxy servers.

How does a cache work and what does it mean to me?
In either scenario, whether a browser or proxy has cached your page, the way that the web server handles the request is the same.