Clippee: A Large-Scale Client/Peer System 

Keno Albrecht, Ruedi Arnold, Roger Wattenhofer Department of Computer Science 
ETH Zurich, Switzerland 

Abstract: This paper introduces a client/peer architecture providing services 
similar to Group Communication systems, but with the scalability of 
peer-to-peer systems and its dynamic behavior. We present Clippee, a first 
prototype of this client/peer architecture. Clippee employs a data replication 
scheme based on an optimistic use of locks, without running an expensive 
consensus protocol. We believe that such a "best effort" approach is an 
important key to large-scale communication systems. We further show the 
applicability of this approach through experimental measurements conducted 
with our prototype.