Overview
1) Determine what type of Filter you wish to use. There are 3 basic types:
- Include (filter in) -- Allows ONLY those hits that match the Filter Pattern
- Exclude (filter out) -- Excludes all hits that match the Filter Pattern
- DynamicURL (translate cryptic URLs into meaningful page names)
2) Determine the Filter Field you wish to perform the pattern matching on. The Urchin interface has the filter fields of the two most common web server software systems, Apache and Microsoft IIS, in an easy-to-use pulldown menu. You should be able to generally determine the correct field from this list. If it is not obvious, please examine the Apache or Microsoft IIS websites.
3) Determine what the Filter Pattern should be. For a simple filter such as one to filter out hits from the Google spider, you can just use the string "Googlebot" (no quotes). NOTE: Filters are case-sensitive, so "googlebot" will not work. You can also use regular expressions -- special characters that perform more complex pattern-matching. A typical regular expression is the asterisk (*), which means simply "all". A common use of the asterisk is in conjunction with some text. For instance, "*bot" will exclude all hits that contain the text string "bot". Regular expressions are a large subject that is beyond the scope of this guide. For more information, one good resource is the O'Reilly book on the subject.
4) Bring up the Urchin admin interface and create the Filter. Filters exist independently of Profiles and Log Sources, so they can be created once and applied any number of times. To create a Filter, click on Configuration >> Filter Manager >> Add. This will take you through the Add Filter Wizard.
5) Apply the Filter to a Profile OR a Log Source. Because Filters exist independently, you can apply them to either a Log Source or a Profile. Because many Profiles will often share one Log Source, it is sometimes more efficient to apply a Filter directly to a Log Source. To apply the Filter, Click on Filter Manager and then the Edit button. Next, click on either the Profiles tab or the Log Sources tab. A list of available items will appear in the "Available" window at left. To move an item in the list to the "Active" box, click on it and then click the right-facing arrow. It will then appear in the right-side box. Click Update to apply any changes.