Modern Algorithms: The Raft Consensus Protocol
Emerging out of a Stanford University Ph.D. thesis in 2014, Raft (Reliable, Replicated, Redundant & Fault-Tolerant) is a less complex alternative to Paxos consensus algorithms. Modern distributed systems (e.g., databases, configuration management systems, container orchestration, etc.) have extensively adopted it due to its reliability & simplicity.
Raft operates by breaking down the consensus problem into three manageable parts - (a) leader election (selecting one node within the cluster as the leader), (b) log replication (the leader writes to a log & replicates that to all other nodes), and safety (achieving consistency through majority voting.)
Today, Raft & its variants drive critical use cases - e.g., consistency & safety (Neo4j), data replication (CockroachDB, MongoDB, etc.), durable queues (RabbitMQ), metadata management (Apache Kafka, ScyllaDB), etc.