Service migration in a distributed virtualization system

Abstract

Cloud applications are usually formed by different components (microservices) that may be located in different virtual and/or physical computers. To achieve the desired level of performance, availability, scalability and robustness in this kind of system is necessary to develop and maintain a complex set of infrastructure configurations. Another approach would be to use a Distributed Virtualization System (DVS) that provides a transparent mechanism that each component could use to communicate with others, regardless of their location and thus, avoiding the potential problems and complexity added by their distributed execution. This communication mechanism already has useful features for developing distributed applications, such as replication support (active and passive) and process migration. In general, process migration is used when a node in the cluster is overloaded or it has been scheduled to be disconnected in order to save energy or to do maintenance tasks in it. When this occurs, it is very important that any application using any service running in that node does not end up being affected by the migration. This article describes the mechanisms used for the migration of server processes between nodes of a DVS cluster in a transparent way for client and server processes, and doing special focus on how to solve the problem of keeping client/server communications active even when the server process location has changed.