... 2002.[5] J. Gray. A census of Tandem system availabilitybetween 1985 and 1990. Tandem Computers Tech-nical Report 90.1, 1990.[6] J. Gray. Why do computers stop and what can be done about it? Symposium ... Suchtools can be built incrementally, with support for addi-tional types of configuration files and constraints addedover time. This idea can be extended in two ways. First,support can be added ... to code modules and/ or operators that can handle them, and distributeddata-flow tracing to help detect, diagnose, and debugperformance and reliability failures. Finally, we believethat research...