Redundancy and Fault Tolerance

This lecture delves into the concepts of redundancy and fault tolerance, essential for constructing dependable systems. The instructor explains how redundancy complements modularity to increase dependability, defining terms like fault, error, and failure. The lecture covers various fault tolerance techniques, such as error correction codes and failover mechanisms, emphasizing the importance of fault models in system design. The instructor also discusses the significance of graceful degradation and the use of leases to manage resources effectively. Additionally, the lecture explores the concept of software rejuvenation as a preventive maintenance strategy to reduce the probability of failures. Through examples and theoretical designs, the lecture provides insights into building dependable systems with efficient recovery mechanisms.