A general framework to solve agreement problems

Agreement problems are among the most important problems designers of distributed systems have to cope with. A way to solve them is to first provide a solution to the Consensus problem and then to reduce each agreement problem to Consensus. This "run-time customizing" approach is particularly relevant when upper layer applications have to solve several distinct agreement problems. We investigate a "compile-time customizing" approach to automatically generate ad hoc agreement protocols. A general agreement framework, characterized by six "versatility" parameters, is defined. Appropriate instantiations of these parameters provide particular agreement protocols. This approach is particularly suited to generate efficient agreement protocols.