HELLO
Handshake: report server info and switch RESP protocol version (2 or 3).
HELLO [protover]Complexity
O(1)
Complexity and compatibility are read out of kevy's implementation, not copied from Redis's reference. Several genuinely differ.
Redis compatibility
Differs
only HELLO [2|3] is honoured — the AUTH and SETNAME tails are parsed off and ignored, because kevy has no AUTH and this form does not set the connection name