Low-cost checkpointing with mutable checkpoints in mobile computing systems

Abstract

Mobile computing raises many new issues, such as lack of stable storage, low bandwidth of wireless channel, high mobility, and limited battery life. These new issues make traditional checkpointing algorithms unsuitable. We introduce the concept of mutable checkpoint, which is neither a tentative checkpoint nor a permanent checkpoint. Mutable checkpoints can be saved anywhere; e.g., the memory or local disk of MHs. In this way, taking a mutable checkpoint avoids the overhead of transferring a large amount of data to the stable storage in MSS over the wireless network. Based on mutable checkpoints, our non-blocking algorithm avoids the avalanche effect, minimizes the number of synchronization messages and forces only a minimum number of processes to take their checkpoints on the stable storage.