Evaluating I/O Scheduling Techniques at the Forwarding Layer and Coordinating Data Server Accesses
Abstract
In this dissertation, we evaluate I/O scheduling techniques for the I/O forwarding layer of supercomputers. We demonstrate that existing algorithms that work to improve spatiality and request size of the access patterns are only partially effective. We propose TWINS, a new scheduling algorithm to coordinate the access of intermediate I/O nodes to the data servers. Our solution decreases concurrency at the latter, a factor proved to negatively affect performance. We are able to improve read performance from shared files by up to 28% over state-of-the-art scheduling algorithms and by up to 50% over not forwarding I/O. Our collaborations to the HPC field accounted for 16 papers and also motivated interactions with researchers from Argonne, BSC, INRIA, and LNCC.
References
Balouek, D., Amarie, A. C., Charrier, G., and Desprez, F. (2013). Adding Virtualization Capabilities to the Grid’5000 Testbed, pages 3–20. Communications in Computer and Information Science. Springer International Publishing.
Boito, F. Z., Kassick, R. V., Navaux, P. O. A., and Denneulin, Y. (2015). Automatic I/O scheduling algorithm selection for parallel file systems. Concurrency and Computation: Practice and Experience.
DOE (2010). The opportunities and challenges of exascale computing. Technical report.
LANL (2006). Los Alamos National Lab MPI-IO Test, User’s Guide.
Ohta, K., Kimpe, D., Cope, J., Iskra, K., Ross, R., and Ishikawa, Y. (2010). Optimization techniques at the I/O forwarding layer. In Proceedings..., pages 312–321. IEEE International Conference on Cluster Computing, IEEE.
Vishwanath, V., Hereld, M., Iskra, K., Kimpe, D., Morozov, V., Papka, M. E., Ross, R., and Yoshii, K. (2010). Accelerating I/O Forwarding in IBM Blue Gene/P Systems. In Proceedings..., SC’10, pages 1–10. 2010 ACM/IEEE International Conference for High Performance Computing, Networking, Storage and Analysis, IEEE.
