Adding Dynamicity to the Uncertainty that Characterizes Distributed Systems: Challenges Ahead

The uncertainties inherent to distributed systems, such as unpredictable message delays and process failures, gave place to a great research effort in the past, where numerous solutions to fault-tolerance mechanisms have been proposed with a variety of guarantees and underlying system assumptions. The advent of new classes of distributed system applications (such as social networks, security, smart objects sharing etc) and technologies (VANET, WiMax, Airborn Networks, DoD Global Information Grid, P2P) are radically changing the way in which distributed systems are perceived. Such emerging systems have a composition, in term processes participating to the system, that is self-defined at run time depending, for example, on their will to belong to such a system, on the geographical distribution of processes etc. In this paper, we point to some of the challenges that have to be addressed by fault-tolerance solutions in the light of such a new dynamicity dimension, and that will motivate our future collaborative work.