Dodging the Cost of Unavoidable Memory Copies in Message Logging Protocols

With the number of computing elements spiraling to hundred of thousands in modern HPC systems, failures are common events. Few applications are nevertheless fault tolerant; most are in need for a seamless recovery framework. Among the automatic fault tolerant techniques proposed for MPI, message logging is preferable for its scalable recovery. The major challenge for message logging protocols is the performance penalty on communications during failure-free periods, mostly coming from the payload copy introduced for each message. In this paper, we investigate different approaches for logging payload and compare their impact on network performance.