Faults and Partial FailuresCloud Computing and SupercomputingUnreliable NetworksNetwork Faults in PracticeDetecting FaultsTimeouts and Unbounded DelaysSynchronous Versus Asynchronous NetworksUnreliable ClocksMonotonic Versus Time-of-Day ClocksClock Synchronization and AccuracyRelying on Synchronized ClocksProcess PausesKnowledge, Truth, and LiesThe Truth Is Defined by the MajorityByzantine FaultsSystem Model and RealitySummary