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Consistency Mechanisms for a Distributed Lookup Service supporting Mobile Applications

Waldhorst, Oliver P.; Lindemann, Christoph

Abstract (englisch):

This paper presents a general-purpose distributed lookup service, denoted Passive Distributed Indexing (PDI). PDI stores entries in form of (key, value) pairs in index caches located in each mobile device. Index caches are filled by epidemic dissemination of popular index entries. By exploiting node mobility, PDI can resolve most queries locally without sending messages outside the radio coverage of the inquiring node. Thus, PDI reduces network traffic for the resolution of keys to values. For keeping index caches coherent, configurable value timeouts implementing implicit invalidation and lazy invalidation caches implementing explicit invalidation are introduced. Inconsistency in index caches due to weak connectivity or node failure is handled by value timeouts. Lazy invalidation caches reduce the fraction of stale index entries due to modified data at the origin node. Similar to index caches, invalidation caches are filled by epidemic distributions of invalidation messages. Simulation results show that with the suitable integration of both invalidation mechanisms, more than 95% of results delivered by PDI index caches are up-to-date for the considered scenario.

Zitationen: 14
Zugehörige Institution(en) am KIT Institut für Telematik (TM)
Publikationstyp Proceedingsbeitrag
Publikationsjahr 2003
Sprache Englisch
Identifikator ISBN: 1581134126
KITopen-ID: 1000088126
Erschienen in Proceedings of the 3rd ACM International Workshop on Data Engineering for Wireless and Mobile Access (MobiDE 2003), San Diego, CA, September 19, 2003
Verlag Association for Computing Machinery (ACM)
Seiten 61-68
Nachgewiesen in Scopus
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