graph TB

    requestLeader[request] --> RPCLeader
    requestFollower[request] --> RPCFollower

    class requestLeader,requestFollower req;
    classDef req fill:transparent,color:#000,stroke-width:1;

    subgraph Leader
        RPCLeader[RPC]
        RaftLeader[Raft]
        StateStoreLeader[State Store]
        FSMLeader[FSM]
    end

    RPCLeader -->|write| RaftLeader
    RPCLeader -->|read| StateStoreLeader
    RaftLeader ---> FSMLeader
    FSMLeader --> StateStoreLeader

    subgraph Follower
        RPCFollower[RPC]
        RaftFollower[Raft]
        StateStoreFollower[State Store]
        FSMFollower[FSM]
    end

    RaftLeader <-.->|consensus and replication| RaftFollower

    RPCFollower -->|forward write to leader| RPCLeader
    RPCFollower -->|read| StateStoreFollower
    RaftFollower --> FSMFollower
    FSMFollower --> StateStoreFollower