Case Study: Social Network Home TimelinesRepresenting Users, Posts, and FollowsMaterializing and Updating TimelinesDescribing PerformanceLatency and Response TimeAverage, Median, and PercentilesUse of Response Time MetricsReliability and Fault ToleranceFault ToleranceHardware and Software FaultsHumans and ReliabilityScalabilityDescribing LoadShared-Memory, Shared-Disk, and Shared-Nothing ArchitecturePrinciples for ScalabilityMaintainabilityOperability: Making Life Easy for OperationsSimplicity: Managing ComplexityEvolvability: Making Change EasySummary