A leader appends entries in its term and replicates them to matching followers.

highlighted = computed this step

The leader appends and replicates

After election, a leader appends entries in its current term. Followers accept the entry when the log prefix matches. Note: append and commit are separate events.

append replicate\text{append replicate}

Append entry

The leader log has 1 entry, and 3 nodes hold that entry. Note: the log cells show the replicated value.

leader entries=1,replicas=3\text{leader entries}=1,\quad \text{replicas}=3

a simplified Raft over a tiny cluster: terms, votes, leader election, and the term-restricted commit rule are exact on these traces; the full safety proof, membership changes, snapshotting, log compaction, and real RPC/timing are beyond these traces - no product claims.

Leader appends commitIndex 0 0 1 2 3 A t0/F t1/C t1/L t1/L B t0/F t1/F t1/F t1/F C t0/F t1/F t1/F t1/F vote tally t1 A:3 leader log A t1:x

Not yet committed

Before advanceCommit, the commitIndex is 0. Note: replication is visible, but commit waits for its own event.

commitIndex=0\text{commitIndex}=0

a simplified Raft over a tiny cluster: terms, votes, leader election, and the term-restricted commit rule are exact on these traces; the full safety proof, membership changes, snapshotting, log compaction, and real RPC/timing are beyond these traces - no product claims.

Leader appends commitIndex 0 0 1 2 3 A t0/F t1/C t1/L t1/L B t0/F t1/F t1/F t1/F C t0/F t1/F t1/F t1/F vote tally t1 A:3 leader log A t1:x

Summary

Appending creates replicated log entries, but commitment is a later rule. Note: this is simplified Raft; the full safety proof, membership changes, snapshots, and real timing are beyond these traces.

append before commit\text{append before commit}