RAFTss

RAFTss refers to a family of distributed consensus algorithms designed to achieve fault tolerance in computer systems. The most well-known is Raft, a consensus algorithm that is designed to be easier to understand than Paxos. Raft was developed by Diego Ongaro and John Ousterhout.

The core idea behind Raft is to divide the problem of distributed consensus into two subproblems: leader election and log replication. In Raft, the cluster of servers is always in one of three states: follower, candidate, or leader. A follower passively receives log entries from the leader and votes in elections. A candidate attempts to become a leader by requesting votes from other servers. The leader is responsible for managing the replicated log and handling client requests.

Log replication is handled by the leader sending AppendEntries RPCs to other servers. If a server receives an AppendEntries RPC with an entry it does not have, it appends the entry to its log. This process ensures that all servers in the cluster maintain an identical log of operations.

Raft's design emphasizes understandability and implementability, making it a popular choice for building reliable distributed systems. It guarantees safety under the assumption that a majority of servers are available and can communicate. Failures of individual servers or network partitions are handled gracefully by the election and replication mechanisms.