The goal of this paper is to assess the value of simple features that are widely available in off-the-shelf CORBA and Java platforms for the implementation of fault-tolerance mechanisms in industry-grade systems. This work builds on knowledge gained at LAAS from previous work on the prototyping of reflective fault tolerant frameworks. We describe how we used the interception and state capture mechanisms that are available in CORBA and Java to implement a simple replication strategy on a small middleware-based system built upon GNU/Linux and JOrbacus. We discuss the benefits and the limits of the resulting system from a practical point of view.

An intrusion-tolerant distributed system is a system which is designed so that any intrusion into a part of the system will not endanger confidentiality, integrity and availability. This approach is suitable for distributed systems, because distribution enables isolation of elements so that an intrusion gives physical access to only a part of the system. In particular, the intrusion-tolerant authentication and authorization servers enable a consistent security policy to be implemented on a set of heterogeneous, untrusted sites, administered by untrusted (but nonconspiring) people. The authors describe how some functions of distributed systems can be designed to tolerate intrusions. A prototype of the persistent file server presented has been successfully developed and implemented as part of the Delta-4 project of the European ESPRIT program.>