FAST will present a new publication on the acceleration of migrations in virtual environments at the 11th Workshop on Virtualization in High-Performance Cloud Computing (VHPC). The VHPC workshop will be held on 23/6/2016 in Frankfurt, Germany, in conjunction with the International Supercomputing Conference - High Performance 2016 (ISC).
Title: Accelerating Application Migration in HPC
Authors: Ramy Gad, Simon Pickartz, Tim Süß, Lars Nagel, Stefan Lankes, André Brinkmann
Abstract: It is predicted that the number of cores per node will rapidly increase with the upcoming era of exascale supercomputers. As a result, multiple applications will have to share one node and compete for the (often scarce) resources available on this node. Furthermore, the growing number of hardware components causes a decrease in the mean time between failures. Application migration between nodes has been proposed as a tool to mitigate these two problems: Bottlenecks due to resource sharing can be addressed by load balancing schemes which migrate applications; and hardware errors can often be tolerated by the system if faulty nodes are detected and processes are migrated ahead of time.
VM migration currently seems to be the most promising technique for such approaches as it provides a strong level of isolation. However, the migration time of virtual machines is higher than the respective migration time on the process level. This can be explained by the additional virtualization layer in the memory hierarchy.
In this paper, we propose a technique for the acceleration of VM migration. We take advantage of the fact that freed memory regions within the guest system are not recognized by the hypervisor. Therefore, we fill them with zeros such that zero-page detection and compression can work more efficiently. We demonstrate that the approach reduces migration time by up to 8% with a negligible overhead for some applications.