An Incremental Crawler for Web Video Based on Content Longevity

The explosive growth of online videos is crucial to the development of video search engines. Search engines use crawlers to retrieve pages and then discover new ones by extracting the pages' outgoing links. However, the ephemeral and persistent content which are distinguished by the web crawlers are also exist on the online video pages and are rarely noticed by video search engines. Based on this observation, we characterize the longevity of content found on the video pages and develop an incremental crawler. In the crawling policy, a practical meaningful method to estimate utility threshold is given. As we show via experiments over real web data, our refresh policy obtain better freshness at lower cost, compared with previous approaches.