A multiserver unikernel for a distributed virtualization system based on coroutines

Abstract

Nowadays, most Cloud applications are developed using MicroService Architecture (MSA). The scalability and performance of them is achieved by executing multiple instances of its components in different nodes of a virtualization cluster. Initially, they were deployed in Virtual Machines (VMs), but they required enough computational, memory, network and storage resources to hold an Operating System (OS), a set of utilities, libraries, and the application itself. By deploying hundreds of these applications, the requirement of resources increases a lot. To minimize them, usually small footprint OS are used. Later, as management tools were improved, the applications began to be deployed in Containers which require even less resources than VMs. Another way to reduce the resource requirements is integrating the application within a Unikernel where only the components used by the application are present. In a previous article, a Unikernel based on a multiserver OS called MUK was presented as a proof of concept. MUK runs as userspace process and its components runs as Linux threads. The communication between servers, tasks and external processes use a mechanism named M3-IPC which is the foundation of a Distributed Virtualization System. In this article a new version named MUK2 is presented which differs from MUK in that its uses coroutines to deploy its components. MUK2 was built to run inside a Container and both technologies facilitate the scattering of applications in a virtualization cluster keeping the isolation properties and minimal attack surface.