Survey of Backward Error Recovery Techniques for Multicomputers Based on Checkpointing and Rollback

For implementing fault-tolerance in multicomputer systems, backward error recovery, based on checkpointing and rollback, is often used. During failurefree operation, the process states are regularly saved, and after a fault is detected, the system is rolled back to a previously saved state. We can distinguish four classes of techniques: semi-automatic techniques, message logging, coordinated checkpointing and hybrid techniques. In this paper a survey is given, and the possibly involved overhead is discussed. This will allow the user to choose an optimal checkpointing and rollback technique for given facilities and applications. The rest of the paper is organised as follows. The overhead (in time, storage, communication) and other requirements and aspects to compare the techniques are presented in section 2. The semiautomatic technique is discussed in section 3, while the classes of user-transparent checkpointing techniques are described in section 4. A comparison is made in section 5, after which some general conclusions are presented in section 6. 2. Aspects for Comparison In this section, topics to compare the different checkpointing and rollback techniques are considered. The overhead, capabilities and constraints of the algorithms must be examined. Keywords—fault-tolerance, backward error recovery, checkpointing, rollback