Abstract: Systems and method are provided for setting a respective reuse flag for a corresponding document in a plurality of documents based on a query-independent score associated with the corresponding document. A document crawling operation is performed on the plurality of documents in accordance with the reuse flag for respective documents in the plurality of documents. This document crawling operation includes reusing a previously downloaded version of a respective document in the plurality of documents instead of downloading a current version of the respective document from a host computer in accordance with a determination that the reuse flag associated with the respective document meets a predefined criterion.

Abstract: Systems and method are provided for setting a respective reuse flag for a corresponding document in a plurality of documents based on a query-independent score associated with the corresponding document. A document crawling operation is performed on the plurality of documents in accordance with the reuse flag for respective documents in the plurality of documents. This document crawling operation includes reusing a previously downloaded version of a respective document in the plurality of documents instead of downloading a current version of the respective document from a host computer in accordance with a determination that the reuse flag associated with the respective document meets a predefined criterion.

Abstract: Systems and method are provided for setting a respective reuse flag for a corresponding document in a plurality of documents based on a query-independent score associated with the corresponding document. A document crawling operation is performed on the plurality of documents in accordance with the reuse flag for respective documents in the plurality of documents. This document crawling operation includes reusing a previously downloaded version of a respective document in the plurality of documents instead of downloading a current version of the respective document from a host computer in accordance with a determination that the reuse flag associated with the respective document meets a predefined criterion.

Abstract: A search engine crawler includes a distributed set of schedulers that are associated with one or more segments of document identifiers (e.g., URLs) corresponding to documents on a network (e.g., WWW). Each scheduler handles the scheduling of document identifiers (for crawling) for a subset of the known document identifiers. Using a starting set of document identifiers, such as the document identifiers crawled (or scheduled for crawling) during the most recent completed crawl, the scheduler removes from the starting set those document identifiers that have been unreachable in each of the last X crawls. Other filtering mechanisms may also be used to filter out some of the document identifiers in the starting set. The resulting list of document identifiers is written to a scheduled output file for use in a next crawl cycle.

Abstract: A search engine crawler includes a scheduler for determining which documents to download from their respective host servers. Some documents, known to be stable based on one or more record from prior crawls, are reused from a document repository. A reuse flag is set in a scheduler record that also contains a document identifier, the reuse flag indicating whether the document should be retrieved from a first database, such as the World Wide Web, or a second database, such as a document repository. A set of such scheduler records are used during a crawl by the search engine crawler to determine which database to use when retrieving the documents identified in the scheduler records.

Abstract: A search engine crawler includes a distributed set of schedulers that are associated with one or more segments of document identifiers (e.g., URLs) corresponding to documents on a network (e.g., WWW). Each scheduler handles the scheduling of document identifiers (for crawling) for a subset of the known document identifiers. Using a starting set of document identifiers, such as the document identifiers crawled (or scheduled for crawling) during the most recent completed crawl, the scheduler removes from the starting set those document identifiers that have been unreachable in each of the last X crawls. Other filtering mechanisms may also be used to filter out some of the document identifiers in the starting set. The resulting list of document identifiers is written to a scheduled output file for use in a next crawl cycle.