Evaluation of On-line Reconfiguration Techniques for a Distributed Avionic Middleware

Abstract

On-board Computers are at the centre of space-faring systems. Commercial Of The Shelf (COTS) components provide higher performance but do not provide fault-tolerance mechanisms. To tackle this, the DLR utilises a distributed system of COTS components, that run a middleware called ScOSA. ScOSA manages nodes in a distributed system and, upon a node failure, mitigates the effects by reconfiguring the system to a configuration that excludes the failed node. An online algorithm was implemented in the middleware of ScOSA, designed as a combination of the online algorithms acquired during literature research. After defining specific requirements for the tailor-made online algorithm, it was tested on the target hardware and by using virtual nodes for its feasibility and scalability. It was compared with the offline situation on time and network usage. The design of an online algorithm for ScOSA proved to be feasible. It was not only capable of creating configurations dynamically but also provided scalability.