A minimal implementation of the Raft consensus algorithm in Rust for learning purposes.

• Leader Election
• Heartbeat mechanism
• Request Vote RPC
• Append Entries RPC
• Log replication
• gRPC network layer
• CLI & Config
• E2E Test script
• HTTP Client API
• Log Snapshot (Optional)
• Persistence (Optional)

src/
├── types.rs      # Core types (Term, NodeId, LogIndex, RaftState)
├── rpc.rs        # RPC messages (RequestVote, AppendEntries)
├── log.rs        # Log entry and storage
├── timer.rs      # Election and heartbeat timers
├── event.rs      # Event types for the event loop
├── node.rs       # RaftNode - core Raft logic
├── raft.rs       # RaftRunner - event loop with network calls
├── server.rs     # gRPC server (receives RPCs)
├── client.rs     # gRPC client (sends RPCs)
├── http.rs       # HTTP API server
├── lib.rs        # Module exports
└── main.rs       # CLI entry point

proto/
└── raft.proto    # gRPC service definition

Build the project:

cargo build --release

Run a 3-node cluster (in separate terminals):

# Terminal 1 - Node 1
./target/release/mini-raft --id 1 --port 50051 --peers "2=[::1]:50052,3=[::1]:50053"

# Terminal 2 - Node 2
./target/release/mini-raft --id 2 --port 50052 --peers "1=[::1]:50051,3=[::1]:50053"

# Terminal 3 - Node 3
./target/release/mini-raft --id 3 --port 50053 --peers "1=[::1]:50051,2=[::1]:50052"

Each node exposes an HTTP API on port gRPC_port + 1000 (e.g., 50051 -> 51051).

Returns the current node status.

curl http://[::1]:51051/status

Response:

{
  "node_id": 1,
  "state": "Leader",
  "term": 5,
  "commit_index": 3
}

Submit a command to the cluster (leader only).

curl -X POST http://[::1]:51051/command \
  -H "Content-Type: application/json" \
  -d '{"command": "set key value"}'

Response (success):

{
  "success": true,
  "index": 4,
  "error": null
}

Response (not leader):

{
  "success": false,
  "index": null,
  "error": "not_leader"
}

TODO: Future versions will include leader_hint field to redirect clients to the current leader.

Returns all log entries.

curl http://[::1]:51051/log

Response:

[
  {"index": 1, "term": 1, "command": "set foo bar"},
  {"index": 2, "term": 1, "command": "set baz qux"}
]

• Raft Paper
• Raft Visualization

MIT