First Workshop on Real, Large Distributed Systems Abstract
Distributed Resource Discovery on PlanetLab with SWORD
David Oppenheimer, EECS Computer Science Division, University of California Berkeley; Jeannie Albrecht, Department of Computer Science and Engineering, University of California San Diego; David Patterson, EECS Computer Science Division, University of California Berkeley; Amin Vahdat, Department of Computer Science and Engineering, University of California San Diego
We describe SWORD, a decentralized service for resource discovery and
service placement. SWORD finds the optimal embedding of a user's resource
request (expressed as a topology of interconnected groups of nodes with
per-node, inter-node, and inter-group constraints expressed as utility
functions) in the topology of available nodes. SWORD consists of two parts:
a multi-attribute distributed range query engine built on top of a
distributed hashtable, and an "optimizer" whose work is parallelized on a
per-query basis. In this paper we focus on SWORD's PlanetLab deployment and
the lessons we have learned from that deployment. We find generally
acceptable performance for our decentralized implementation, although we
find that even a very small (two-node) ``centralized'' solution offers
superior performance, in terms of median distributed query latency, for a
reporting and querying node population the size of PlanetLab. Our deployment
has led to qualitative observations on the usefulness of a DHT as a service
building block, the benefits and dangers of automatic application restart,
and the benefits of exporting a simple external interface that is
semantically close to the service's internal representation of user queries.
- View the full text of this paper in HTML and PDF.
- If you need the latest Adobe Acrobat Reader, you can download it from Adobe's site.