Service Recovery for Composite Service in MANETs

There has been recent interest in service composition over MANETs, to exploit heterogeneous resources of distributed nodes. Such composition service executions, however, suffer from the characters of frequent link failures and dynamic topology of MANETs. In this paper, we study the recovery problem of decentralized composite service execution over MANETs. We propose four strategies based on three functional entities: atomic service timer, reselection and cache. Atomic service timer sets a timer for each atomic service to alarm the failure as soon as possible. Reselection makes recovery process select a new provider for pre-failed service. Cache aims at reusing the result of successful atomic service to save the resource and time. The four recovery strategies are atomic service timer with resending strategy (ASD), atomic service timer with reselection strategy (ASL), atomic service timer with resending and cache (ASDC), atomic service timer with reselection and cache (ASLC). The simulation results show that four strategies improve the performance of the execution without recovery significantly. In addition, the strategies with cache perform better than strategies without cache on the failure rate and the execution time.