Summary of open issues in the architecture

Summary of open issues in the architecture

Open issues in Event Notification

• Implementing content-based subscription on top of the topic-based substrate
• Scalability on one hand, but no forwarders (that aren't interested in the event) on the other

Open issues in Subscription Clustering

• Partition algorithm
  • Centralized or decentralized
  • Online or offline
• (Yotam - more?...)

Open issues in multicast

• Building the multicast tree(s)
  • Centralized or decentralized?
  • Minimize bandwidth for peers who don't participate in the multicast
  • Relation to peer incentives?
• Simultaneous download from multiple peers
• Solving the trade-off of multiple package trees

Open issues in persistent storage

• Implementing permissions (and general security)
  • For writing (and reading?) into channels
  • For creating and deleting channels
• Downgrading OceanStore (or similar)
  • Getting the latest version
  • "Primary replica" (using today's mirrors?)
• Deleting obsolete versions
• Efficiently downloading related packages
• Incentives for peers to share files

Open issues in file sharing

• Finding as many replicas as possible for a quick download.
• Employing rateless codes.
• Using spontaneous multicast ? when and how?
• Efficiently downloading related files.

General open issues

• Security architecture for the whole system
  • Defending against Sybil attacks
  • Trust system for rating peers and files
• TCP-friendliness of the protocols
• Criteria for simulation and comparison
• Peer incentives for helping the community