Synchronising Service Compositions in Dynamic Ad Hoc Environments

Abstract

Abstract-Service compositions in dynamic ad hoc environments face frequent changes in the network and service topology. Late service binding is a way to adapt to runtime changes but requires additional communication over error-prone and energy-constrained networks. In particular, synchronising parallel service flows relies on steady message exchange when mutually unknown service providers have to agree on a common merge node. Binding the merge node early through a single entity reduces the need for coordination. However, it compromises flexibility and may nonetheless increase communication as the decision entity has only partial view of the system. This paper proposes a multi-party late binding protocol as a solution for flexible, communication-aware service composition in dynamic ad hoc environments. The protocol integrates the discovery of unknown synchronisation partners with the exchange of binding suggestions to reduce communication. We embed this protocol in our model for opportunistic service composition and evaluate it against an early binding approach. Simulation results show that while being overall equally successful, late service binding outperforms early binding with respect to communication overhead and response time.

Multi-Strategy Dynamic Service Composition in Opportunistic Networks

“…The advantage of this solution is that it addresses each selected service provider only once, and requires less data exchanges than a traditional consecutive approach that runs in two phases: a binding phase to select the providers, then a phase to invoke them. In [23], the authors propose an extension of the solution they described in [8,24]. This extension makes it possible to invoke several providers in parallel, thus creating several branches in the service composition graph.…”

Towards In-network Aggregation for People-Centric Sensing

“…The role of a service router was introduced by our synchronisation protocol [4] to handle requests with parallel execution paths. Service routers use the structure of the composite and the observed allocation history to route synchronisation messages between mutually unknown synchronisation partners that must agree on a common provider for the merge service.…”

“…This paper proposes opportunistic service composition, a composition protocol that defers all interactions with peers to the latest possible moment. In contrast to our previous work [3,4], it explores service composition from the perspective of autonomous service providers and how on-demand discovery, just in time release, and observation of the composition progress enables them to cooperatively control their availability. Focusing on the composition management within the ad hoc network, the paper leaves the integration with the cloud service to future work.…”