LIGHT: A Query-Efficient Yet Low-Maintenance Indexing Scheme over DHTs

DHT is a widely used building block for scalable P2P systems. However, as uniform hashing employed in DHTs destroys data locality, it is not a trivial task to support complex queries (e.g., range queries and k-nearest-neighbor queries) in DHT-based P2P systems. In order to support efficient processing of such complex queries, a popular solution is to build indexes on top of the DHT. Unfortunately, existing overDHT indexing schemes suffer from either query inefficiency or high maintenance cost. In this paper, we propose Lightweight Hash Tree (LigHT) -- a query-efficient yet low-maintenance indexing scheme. LigHT employs a novel naming mechanism and a tree summarization strategy for graceful distribution of its index structure. We show through analysis that it can support various complex queries with near-optimal performance. Extensive experimental results also demonstrate that, compared with state-of-the-art over-DHT indexing schemes, LigHT saves 50%-75% of index maintenance cost and su...

• Type: Journal
• Year: 2010
• Where: TKDE
• Authors: Yuzhe Tang, Shuigeng Zhou, Jianliang Xu
• Keywords: Complex Queries, DHT-based P2P, Education, P2P Systems, TKDE 2010