Virtual System Environments

Distributed and parallel systems are typically managed with "static" settings: the operating system (OS) and the runtime environment (RTE) are specified at a given time and cannot be changed to tit an application's needs. This means that every time application developers want to use their application on a new execution platform, the application has to he ported to this new environment, which may be expensive in terms of application modifications and developer time. However, the science resides in the applications and not in the OS or the RTE. Therefore, it should be beneficial to adapt the OS and the RTE to the application instead of adapting the applications to the OS and the RTE. This document presents the concept of Virtual System Environments (VSE), which enables application developers to specify and create a virtual environment that properly fits their application's needs. For that four challenges have to be addressed: (i) definition of the VSE itself by the application developers, (ii) deployment of the VSE, (iii) system administration for the platform, and (iv) protection of the platform from the running VSE. We therefore present an integrated tool for the definition and deployment of VSEs on top of traditional and virtual (i.e., using system-level virtualization) execution platforms. This tool provides the capability to choose the degree of delegation for system administration tasks and the degree of protection from the application (e.g.. using virtual machines). To summarize, the VSE concept enables the customization of the OS/RTE used for the execution of application by users without compromising local system administration rules and execution platform protection constraints.