1. Conclusions in Peer-to-Peer Systems Παρουσίαση: Τάσος Καραγιάννης, Σπυριδούλα Μαργαρίτη, Κώστας Στεφανίδης, Θοδωρής Τσώτσος

2. Peer-to-Peer Systems2 Advantages – Disadvantages Advantages –Scalability –Easy and cheap to built –Fault tolerance –Load Balance –Elimination of network bottlenecks –Autonomy –Availability –Reliability –No-administration –Avoidance of legal constraints Disadvantages –Complexity (join, look up) –Incomplete look up –Communication cost –Network overhead –Maintenance cost –Security

3. Peer-to-Peer Systems3 Examples of Applications File sharing systems –Kazaa, Gnutella, Soulseek, etc Distributed Computation –Seti@Home Distributed Databases –Data are spread across the network Cooperative Mirroring –Load balance across all servers (using replication and caching)

4. Peer-to-Peer Systems4 Interesting Issues Chord Ring –Simple topology, efficient look up and join, small routing information Routing Indices –Alternative approach to flooding –More efficient and less network overhead Shortcuts –Connecting nodes with similar interests SONs –Clustering nodes accordingly to their content Caching and replication –Cached results for future use

5. Peer-to-Peer Systems5 Best Paper Chord: A Scalable Peer-to-peer Lookup Service for Internet Applications –Clever concept –Simple structure (just a ring) –Complete paper

6. Peer-to-Peer Systems6 Main Issues for Future Work Clustering techniques without a-priori knowledge of existing clusters Cycle prediction and elimination –Unstructured systems (too many messages) –Routing indices (inaccurate indices) Security –Anonymity –Authenticity

7. Peer-to-Peer Systems7 END