An efficient recovery scheme for mobile computing environments

This paper presents an efficient recovery scheme based on checkpointing and message logging for mobile computing systems. For the efficient management of checkpoints and message logs, a movement-based scheme is proposed. Mobile hosts carrying their recovery information to the nearby mobile support station can recover instantly in case of a failure, however, the cost to transfer the recovery information must be high. On the other hand, the recovery information remaining dispersed over a number of support stations visited by mobile hosts must incur very high recovery cost. To balance the failure-free operation cost and the recovery cost, in the proposed scheme, the recovery information of a mobile host remains at the visited support stations while the host moves within a certain range. Only when the host moves out of the range, the recovery information is transferred to a nearby mobile support station. As a result, the proposed scheme can control the information transfer cost as well as the recovery cost.