Webbots, Spiders, and Screen Scrapers, 2nd Edition

Final Thoughts

Now that you know how to automate the task of launching webbots from both scheduled and nonscheduled events, it’s time for a few words of caution.

Determine the Webbot’s Best Periodicity

A common question when deploying webbots is how often to schedule a webbot to check if data has changed on a target server. The answer depends on your need for stealth and how often the target data changes. If your webbot must run without detection, you should limit the number of file accesses you perform, since every file your webbot downloads leaves a clue in the server’s log file. Your webbot becomes increasingly obvious as it creates more and more log entries.

The periodicity of your webbot’s execution may also hinge on how often your target changes. ...