A five-level static cache architecture for web search engines
Author
Ozcan, R.
Altingovde, I. S.
Cambazoglu, B. B.
Junqueira, F. P.
Ulusoy, Özgür
Date
2012Source Title
Information Processing & Management
Print ISSN
0306-4573
Publisher
Elsevier Ltd
Volume
48
Issue
5
Pages
828 - 840
Language
English
Type
ArticleItem Usage Stats
113
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86
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Abstract
Caching is a crucial performance component of large-scale web search engines, as it greatly helps reducing average query response times and query processing workloads on backend search clusters. In this paper, we describe a multi-level static cache architecture that stores five different item types: query results, precomputed scores, posting lists, precomputed intersections of posting lists, and documents. Moreover, we propose a greedy heuristic to prioritize items for caching, based on gains computed by using items' past access frequencies, estimated computational costs, and storage overheads. This heuristic takes into account the inter-dependency between individual items when making its caching decisions, i.e.; after a particular item is cached, gains of all items that are affected by this decision are updated. Our simulations under realistic assumptions reveal that the proposed heuristic performs better than dividing the entire cache space among particular item types at fixed proportions. © 2010 Elsevier Ltd. All rights reserved.
Keywords
Query processingStatic caching
Web search engines
Access frequency
Cache architecture
Caching decisions
Computational costs
Greedy heuristics
Inter - dependencies