Fault and Intrusion Tolerance on the Basis of Virtual Machines
Hans P. Reiser, Rüdiger Kapitza · 2008
Fault and intrusion tolerance is an important paradigm for building distributed systems that work in spite of accidental and malicious faults. This paper discusses how to harness virtualization technol-ogy for building such dependable systems. We show that virtual-ization promotes a hybrid fault model that allows tolerating mali-cious intrusions in application domains with little overhead. The proposed architecture features mechanisms for supporting hetero-geneity of the replicas. A hypervisor-based replication controller achieves perpetual operation through periodic proactive recovery of the replicas. Re-mapping of state storage between virtual ma-chines speeds up the state transfer of a stateful replicated service. Our VM-FIT prototype implements the core functionality of such a virtualization-based replication architecture. We present some performance measurements and close with a discussion of future research directions. 1