 
Summary: Sparser: A paradigm for running distributed
algorithms
Yehuda Afek Moty Ricklin
Computer Science Department,
Raymond and Beverly Sackler Faculty of Exact Sciences,
Tel Aviv University
RamatAviv 69978
Israel
Abstract
This paper introduces a transformer for improving the communication complexity of
several classes of distributed algorithms. The transformer takes a distributed algorithm
whose message complexity is O(f \Delta m) and produces a new distributed algorithm to
solve the same problem with O(f \Delta n log n+m log n) message complexity, where n and m
are the total number of nodes and links in the network, and f is an arbitrary function
of n and m.
Applying our paradigm to the standard all shortest paths algorithm [Gal76, Gal82,
Seg83] yields a new algorithm which solves the problem in O(n 2 log n) messages (The
previous best that we know of is O(m \Delta n) messages). When applied to the O(m \Delta log 3 n)
breadthfirst search algorithm of Awerbuch and Peleg [AP90a] our paradigm yields an
O(m+ n \Delta log 4 n) messages algorithm.
