Using lightweight virtual machines to achieve resource adaptation in middleware

Current middleware does not offer enough support to cover the demands of emerging application domains, such as embedded systems or those featuring distributed multimedia services. These kinds of applications often have timeliness constraints and yet are highly susceptible to dynamic and unexpected changes in their environment. There is then a clear need to introduce adaptation in order for these applications to deal with such unpredictable changes. Resource adaptation can be achieved by using scheduling or allocation algorithms, for large-scale applications, but such a task can be complex and error-prone. Virtual machines (VMs) represent a higher-level approach, whereby resources can be managed without dealing with lower-level details, such as scheduling algorithms, scheduling parameters and so on. However, the overhead penalty imposed by traditional VMs is unsuitable for real-time applications. On the other hand, virtualisation has not been previously exploited as a means to achieve resource adaptation. This study presents a lightweight VM framework that exploits application-level virtualisation to achieve resource adaptation in middleware for soft real-time applications. Experimental results are presented to validate the approach.