Fault-Recovery and Coherence in Internet of Things Choreographies

Facilitating the creation of applications for the Internet of Things IoT is a major concern to increase its development. D-LITe, our previous work, introduces genericity by providing a universal programming interface. Objects are dynamically configured to have their own behaviour, and their actions/reactions are considered as part of a whole application. D-LITeful Objects describe their capabilities, receives the application logic to be executed, and interacts with other. The application is seen as a choreography of behaviours. But the main issue of choreographies is the loss of coherence. Because of their unreliability, some networks used in IoT may introduce de-synchronization, leading to interactions errors. We propose to reintroduce coherence in order to keep the advantages of choreography while dealing with this main issue. An overlay of logical check-points defines the dependence between the coherent states of objects and triggers re-synchronizations. This paper ends with a discussion on the trade-off between the checking cost and the reliability improvement.