Message Induced Soft Chekpointing for Recovery in Mobile Environments

Checkpointing is one of the commonly used techniques to provide fault tolerance in distributed systems so that the system can operate even if one or more components have failed. However, mobile computing systems are constrained by low bandwidth, mobility, lack of stable storage, frequent disconnections and limited battery life. Hence checkpointing protocols which have fewer checkpoints are preferred in mobile environment. Since MHs are prone to failure, so they have to transfer a large amount of checkpoint data and control information to its local MSS which increases bandwidth overhead. In this paper we propose a new soft checkpointing scheme for mobile computing systems. These soft checkpoints are saved locally in the host. Locally stored checkpoints do not consume network bandwidth and can be created in less time. Before disconnecting from the MSS, these soft checkpoints are converted to hard checkpoints and are sent to MSSs stable storage. In this way, taking a soft checkpoint avoids overhead transferring large amount of data to the stable storage MSSs.