Lecture 4: Primary-Backup Replication

The podcast delves into fault tolerance and replication strategies for high availability in servers, particularly focusing on VMware FT. It distinguishes between fail-stop failures and other types of errors, like software bugs, which replication cannot address. The discussion covers state transfer versus replicated state machine approaches, highlighting the advantages and disadvantages of each, and emphasizes the importance of independent failures in replicas. It also addresses the economic considerations of replication, questioning whether the cost of redundant resources is justified by the value of continuous service. The podcast further explores the intricacies of VMware FT, including its virtual machine environment, the logging channel for replicating events, and the output rule to prevent inconsistencies during failover, and also addresses the challenges of non-deterministic events, multi-core parallelism, and network partitions, offering detailed explanations and solutions for maintaining synchronized replicas.