A Scalable content-addressable network

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A Scalable content-addressable network

• Presenter Baoning Wu

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Motivation

• Many peer-to-peer systems appear, but most of
  them are not scalable.
• Napster needs a central server to store index of
  all files.
• Gnutella floods request with a certain scope.
• Can we have a scalable p2p file distribution
  system?

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CAN (content-addressable network)

• Scalable indexing mechanism is crucial in
  scalable p2p systems.
• Hash table is used!
• (key, value) pair
• Each CAN node stores a chunk(zone) of the entire
  hash table

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Design

• D-dimensional Cartesian co-ordinate space
• Map key to a point P with a determined hash
  function
• Routing the request if the point P is not owned
  by the requesting node or its immediate neighbors.

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Picture
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Routing detail

• Each CAN node maintains coordinate routing table
  that holds the IP address and virtual coordinate
  zone of its neighbors.
• Routing a message towards its destination by
  simple greedy forwarding to the neighbor with
  coordinated closest to the destination
  coordinates.

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Design improvement Multi-dimensioned coordinate
spaces
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Design improvement Multiple coordinate spaces
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Design improvement multiple dimensions vs.
multiple realities
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Design improvementRTT weighted routing
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Design improvementmultiple nodes share a zone
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Design improvement multiple hash functions
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Design improvementtopologically-sensitive
construction
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Review

• Dimensionality
• Number of realities
• Number of peer nodes per zone
• Number of hash functions
• Use of RTT weighted routing metric
• Use of topologically-sensitive construction

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• QUESTIONS?