Departmental Papers (CIS)

Date of this Version

June 2004

Document Type

Conference Paper


Postprint version. Copyright ACM, 2004. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 2004 ACM SIGMOD international conference on Management of data, pages 935-936.
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NOTE: At the time of publication, author Boon Thau Loo was affiliated with the University of California at Berkeley. Currently (March 2007), he is a faculty member in the Department of Computer and Information Science at the University of Pennsylvania.


We are developing a distributed query processor called PIER, which is designed to run on the scale of the entire Internet. PIER utilizes a Distributed Hash Table (DHT) as its communication substrate in order to achieve scalability, reliability, decentralized control, and load balancing. PIER enhances DHTs with declarative and algebraic query interfaces, and underneath those interfaces implements multihop, in-network versions of joins, aggregation, recursion, and query/result dissemination. PIER is currently being used for diverse applications, including network monitoring, keyword-based filesharing search, and network topology mapping. We will demonstrate PIER's functionality by showing system monitoring queries running on PlanetLab, a testbed of over 300 machines distributed across the globe.



Date Posted: 08 March 2007