Towards Fault-Tolerant Energy-Efficient High Performance Computing in the Cloud

In cluster computing, power and cooling represent a significant cost compared to the hardware itself. This is of special concern in the cloud, which provides access to large numbers of computers. We examine the use of ARM-based clusters for low-power, high performance computing. This work examines two likely use-modes: (i) a standard dedicated cluster, and (ii) a cluster of pre-configured virtual machines in the cloud. A 40-node department-level cluster based on an ARM Cortex-A9 is compared against a similar cluster based on an Intel Core2 Duo, in contrast to a recent similar study on just a 4-node cluster. For the NAS benchmarks on 32-node clusters, ARM was found to have a power efficiency ranging from 1.3 to 6.2 times greater than that of Intel. This is despite Intel´s approximately five times greater performance. The particular efficiency ratio depends primarily on the size of the working set relative to L2 cache. In addition to energy-efficient computing, this study also emphasizes fault tolerance: an important ingredient in high performance computing. It relies on two recent extensions to the DMTCP checkpoint-restart package. DMTCP was extended (i) to support ARM CPUs, and (ii) to support check pointing of the Qemu virtual machine in user-mode. DMTCP is used both to checkpoint native distributed applications, and to checkpoint a network of virtual machines. This latter case demonstrates the ability to deploy pre-configured software in virtual machines hosted in the cloud, and further to migrate cluster computation between hosts in the cloud.