A spider trap (or crawler trap) is a set of web pages that may intentionally or unintentionally be used to cause a web crawler or search bot to make an infinite number of requests or cause a poorly constructed crawler to crash. Web crawlers are also called web spiders, from which the name is derived. Spider traps may be created to "catch" spambots or other crawlers that waste a website's bandwidth. They may also be created unintentionally by calendars that use dynamic pages with links that continually point to the next day or year.
Common techniques used are:
- creation of indefinitely deep directory structures like http://foo.com/bar/foo/bar/foo/bar/foo/bar/.....
- dynamic pages like calendars that produce an infinite number of pages for a web crawler to follow.
- pages filled with a large number of characters, crashing the lexical analyzer parsing the page.
- pages with session-id's based on required cookies.
There is no algorithm to detect all spider traps. Some classes of traps can be detected automatically, but new, unrecognized traps arise quickly.
Read more about Spider Trap: Politeness, See Also
Famous quotes containing the words spider and/or trap:
““Will you walk into my parlor?” said the spider to the fly;
“‘Tis the prettiest little parlor that ever you did spy.
The way into my parlor is up a winding stair,
And I have many pretty things to show when you are there.””
—Mary Howitt (1799–1888)
“The little lifting helplessness, the queer
Whimper-whine; whose unridiculous
Lost softness softly makes a trap for us.
And makes a curse.”
—Gwendolyn Brooks (b. 1917)