Review: Pastry

Pastry is basically a distributed hash-table system upon which
peer-to-peer applications like file storage systems can be built. The
novel feature of Pastry is its desire to place adjacent nodes (in key
space) over diverse geographic locations. The intuition is that by
placing adjacent key-space nodes over a diverse area, the key-space is
robust against physical failures.

Like most DHT systems, Pastry also suffers from requiring exact-key
lookups. There is no mechanism for performing fuzzy matches. The
biggest weakness of the Chord paper is lack of evaluation for the
stability of the system in the face of constant churn. They provide
tests for Pastry's ability to recover its keyspace in the event of
failures as well stating that an average of 57 RPCs per node were
needed to repairing tables after node failures. However, a live
system will experience failures, joins, and lookups all
simultaneously.
Received on Mon Nov 07 2005 - 03:21:35 EST