Efficient partitioning strategies for distributed web crawling

• Published in: Information Networking. Towards Ubiquitous Networking and Services pp. 544 - 553
• Main Authors: Exposto, José, Macedo, Joaquim, Pina, António Manuel Silva, Alves, Albano Agostinho Gomes, Rufino, José
• Format: Conference Proceeding Book Chapter
• Language: English
• Published: Berlin, Heidelberg Springer 2008; Springer Berlin Heidelberg
• Series: Lecture Notes in Computer Science
• Subjects: Crawling; Download Time; Exchange Time; Information retrieval; Link Graph; Partitioning Strategy; Round Trip Time; Web space
• ISBN: 9783540895237; 354089523X
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-540-89524-4_54

This paper presents a multi-objective approach to Web space partitioning, aimed to improve distributed crawling efficiency. The investigation is supported by the construction of two different weighted graphs. The first is used to model the topological communication infrastructure between crawlers and Web servers and the second is used to represent the amount of link connections between servers' pages. The values of the graph edges represent, respectively, computed RTTs and pages links between nodes. The two graphs are further combined, using a multi-objective partitioning algorithm, to support Web space partitioning and load allocation for an adaptable number of geographical distributed crawlers. Partitioning strategies were evaluated by varying the number of partitions (crawlers) to obtain merit figures for: i) download time, ii) exchange time and iii) relocation time. Evaluation has showed that our partitioning schemes outperform traditional hostname hash based counterparts in all evaluated metric, achieving on average 18% reduction for download time, 78% reduction for exchange time and 46% reduction for relocation time. Fundação para a Ciência e a Tecnologia (FCT)