When I was recently reading the recent paper by P. Druschel’s group on “Experiences in building and operating ePOST..” , which will appear in Eurosys, I was left with the impression that p2p applications that have lots of persistent state (e.g. mail server, file backup, or file system) may be pretty difficult to realize using p2p.

Here are some questions that came to my mind (should be vastly expanded)

• What type of p2p applications have been designed and deployed so far (do they have certain characteristics in common)
• What type of applications can be/should be implemented using the p2p paradigm
• What type of applications may be very difficult/(close) to impossible to be implemented using the p2p paradigm.
• What is the impact of the “environment” (e.g. Internet in large as compared to much more controlled context such as a single organization) on the design choices of p2p systems