Common Contracts
1 similar null contracts
Lasaro Camargos Unicamp lasaro@ic.unicamp.brJanuary 16th, 2008
Agents in agreement protocols play well distinct roles. Proposers propose values to the acceptors, which will ac- cept proposals and inform the learners so they detect that an agreement has been reached. A fourth role is that of the coordinator, who filters the proposals from proposers to acceptors. While proposers, learners, and coordina- tors are easily replaced, substituting an acceptor is pro- hibitive. Protocols that do not employ a coordinator are less resilient to acceptor failures. Protocols that use one coordinator are more resilient to acceptor failures, at the expense of one extra communication step even in the ab- sence of failures. Moreover, they require replacing the coordinator as soon as it fails, a reconfiguration that, although relatively inexpensive, diminishes the protocol availability. Hence, either option, i.e, one or zero coordi- nator, has its drawbacks. In previous works, we have pre- sented an alternative: multicoordinated agreement proto- cols. Such protocols
