High Availability, Scalable Storage, Dynamic Peer Networks: Pick Two: "Abstract
Peer-to-peer storage aims to build large-scale, reliable
and available storage from many small-scale unreliable,
low-availability distributed hosts. Data redundancy
is the key to any data guarantees. However, preserving
redundancy in the face of highly dynamic membership
is costly. We use a simple resource usage model to measured
behavior from the Gnutella file-sharing network to
argue that large-scale cooperative storage is limited by
likely dynamics and cross-system bandwidth —not by
local disk space. We examine some bandwidth optimization
strategies like delayed response to failures, admission
control, and load-shifting and find that they do not
alter the basic problem. We conclude that when redundancy,
data scale, and dynamics are all high, the needed
cross-system bandwidth is unreasonable."