• Examples:
        • Failure to send raft message to a remote peer
    • Notice: Normal, but important (uncommon) log information.

      • Examples:
        • Add a new node into the cluster
        • Add a new user into auth subsystem
    • Debug: Everything is still fine, but even common operations may be logged, and less helpful but more quantity of notices.

      • Examples:
        • Send a normal message to a remote peer