Stone Steps Inc.

Article ID: Q20051224-01

Q: Why Stone Steps Webalizer reports more visits than the original Webalizer?

A:A visit is defined as a series of subsequent HTTP requests (hits) made by the same website visitor, which is identified by the IP address, with the maximum time between requests not exceeding the value of the visit timeout. The default visit timeout is 30 minutes. Consider the following timeline, where each x represents an HTTP request of any type (i.e. pages, graphics, style sheets, etc) made by the same visitor:

        ~~~~ visit ~~~~                  ~~ visit ~~
       v               v                v           v
 ------x---x------x-x--x----------------x---x-x-----x----------> 
       ^~~~^           ^~~~~~~~~~~~~~~~~^                  time
       5 min                40 min 

Because the time between two subsequent requests in the middle is greater than the visit timeout, the earlier request will be considered as the last request of the first visit and the latter one will be considered as the first request of the new visit. In this case, Stone Steps Webalizer will report two visits.

Now consider a slightly different timeline, where each p represents an HTTP request of a page (e.g. PHP, ASP, HTML, etc) and each o represents a request of a resource of some other type (e.g. images, style sheets, etc):

        ~~~~ visit ~~~~                  ~~ visit ~~
       v               v                v           v
 ------o---p------o-o--o----------------o---o-o-----o----------> 
       ^~~~^           ^~~~~~~~~~~~~~~~~^                  time
       5 min                 40 min 

Stone Steps Webalizer ignores the type of the requested resource when counting visits and will make no distinction between the first and the second case. The original Webalizer (v2.1.10), however, only considers page requests when counting visits and will report only one visit in the second case.

As a result of this difference in the visit counting logic, the number of visits reported by Stone Steps Webalizer will be higher than the number of visits reported by the original Webalizer. Consequently, the number of visits reported for each host in the monthly hosts report may not be less than one (i.e. each visitor is considered to make at least one visit), while it was possible to see the number of visits reported by the original Webalizer as zero for those hosts that did not request any pages.