Nomad: Cross-Platform Computational Offloading and Migration in Femtoclouds Using WebAssembly
Mohammed Nurul-Hoque, Khaled A. Harras
Abstract
Latency and privacy concerns, together with the spread of IoT devices, have recently sparked interest in edge computing and computational offloading to the edge and beyond. Portability and migratability are important requirements to achieve a stable edge femtocloud offloading platform. Due to the inherent heterogeneity of the edge, code compatibility is one of the core challenges towards achieving those goals. In this paper, we examine how popular technologies achieve portability and migratability, and the advantages and limitations of each method in light of established standards and current research. We argue that WebAssembly has many advantages as a platform for femtocloud offloading. Next, we implement Nomad, an interpreter-based environment, to run WebAssembly that is capable of live-migrating across operating systems and hardware architectures. We evaluate Nomad and examine the effect of migration on performance, startup and migration delays, and cross-platform migration. We find that migration, even cross-platform, adds less than 5% overhead to performance and fixed delays are less than 2ms in most scenarios.