Manetho is a new transparent rollback_recovery protocol for long-running distributed computations. It uses a novel combination of antecedence graph maintenance, uncoordinated check pointing, and sender-based message logging. Manetho simultaneously achieves the advantages of pessimistic message logging, namely limited rollback and fast output commit, and the advantage of optimistic message logging, namely low failure-free overhead. These advantages come at the expense of a complex recovery scheme