Section: New Results

Emulation of Volatile Systems

Participants : Thomas Largillier, Benjamin Quetier, Sylvain Peyronnet, Thomas Hérault, Franck Cappello.

In the process of developping grid applications, people need to often evaluate the robustness of their work. Two common approaches are simulation, where one can evaluate his software and predict behaviors under conditions usually unachievable in a laboratory experiment, and experimentation, where the actual application is launched on an actual grid. However simulation could ignore unpredictable behaviors due to the abstraction done and experimation does not guarantee a controlled and reproducible environment, and simulation often introduces a high level of abstraction that make the discovery and study of unexpected, but real, behaviors a rare event.

In this work, we proposed an emulation platform for parallel and distributed systems including grids where both the machines and the network are virtualized at a low level. The use of virtual machines allows us to test highly accurate failure injection since we can destroy virtual machines, and network virtualization provides low-level network emulation. Failure accuracy is a criteria that evaluates how realistic a fault is. The accuracy of our framework has been evaluated through a set of micro benchmarks and a very stable P2P system called Pastry.

We are in the process of developping a fault injection tool to work with the platform. it will be an extension of the work started in the tool Fail. The interest of this work is that using Xen virtual machines will allow to model strong adversaries since it is possible to have virtual machines with shared memory. These adversaries will be stronger since they will be able to use global fault injection strategies.