The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 2002
Filed:
Nov. 02, 1999
Marc Alexander Najork, Palo Alto, CA (US);
Clark Allan Heydon, San Francisco, CA (US);
Alta Vista Company, Palo Alto, CA (US);
Abstract
A method and system for scheduling downloads in a web crawler. A web crawler may use multiple threads to download documents from the world wide web. Both threads and queues are identified by numerical ID's. Each thread in the web crawler is assigned to dequeue from a queue until the assigned queue is empty. Each thread enqueues URL's as new URL's are discovered in the course of downloading web pages. In one embodiment, when a thread discovers a new URL, a numerical function is performed on the URL's host component to determine the queue in which to enqueue the new URL. In another embodiment, each queue in a web crawler may be dynamically assigned to a host computer so that URL's enqueued into the same queue all have the same host component. When a queue becomes empty, a new host may be dynamically assigned to it. In both embodiments, when all the threads are dequeuing in parallel from each of the respectively assigned queues, no more than one request to one host computer is made at the same time.