Sistemi peer to peer (Peer to peer systems and blockchains)

The course introduces the methodologies and techniques for the development of peer to peer systems. The course presents both the basic technologies and a set of formal tools for these systems. Some concrete examples will be shown, for instance the e-Mule, Spotify, BitTorrent P2P applications. Some lessons will be devoted to the use of P2P technologies in cloud environments, with special reference to highly scalable data storage (e.g.: Dynamo, Cassandra). The final part of the course presents a set of highly scalable simulators for P2P systems. It is possible to implement a didactic project requiring the development of a set of simulations. Every year a set of project proposals will be presented, but the student may also present an original propose which must be approved by the teacher. Alternatively, the student may choose a written examination.

• • Introduction: P2P and Big Data as Complex Networks
  • P2P Systems: Content Search and Distribution
    • Unstructured Overlays: Flooding, Random Walks
    • Structured Overlays: Distributed Hash Tables (DHT)
      • The Chord DHT: A Markov chain Model of Routing in Chord
    • Case Studies:
      • eMule: the KAD implementation of the Kademlia DHT
      • Bittorrent: a Content Distribution Network, Game based Cooperation
      • Bitcoin: Digital currency. Anonimicity in P2P networks
    • Simulation Environments for P2P Systems: Peersim, PerfactSim
  • Models for P2P and Big Graphs:
    • Random Graphs and Small Worlds
    • Small world navigability: Watts Strogatz and Kleinberg Models
    • Complex networks navigability: case studies
      • The Darknet Freenet, a Small World Network
      • Big Social Graphs: Geographical Routing
  • Vertex Centric Approaches:
    • P2P Asynchronous Models: Epidemic Approaches
    • Global Models for Big Graph Computing: the Bulk Synchronous Computing Model
  • Distributed Supports for Big Graphs Frameworks
    • Facebook cloud: a DHT in the cloud
    • Google's globally-distributed Database
    • Distributed Supports for BSP models

Final Project or Written Examination. The oral examination may be waived if the student passes the mid term and the final term