ZMPOP

ZMPOP checks the given keys in order and pops from the first one that holds a non-empty sorted set. It removes up to count members (default 1), all from that one sorted set: the lowest scores with MIN, the highest with MAX. The key is deleted when it becomes empty.

To wait when every sorted set is empty, use BZMPOP.

Options

Option	Effect
numkeys	How many keys follow. Must be greater than 0.
MIN	Pop the members with the lowest scores.
MAX	Pop the members with the highest scores.
COUNT count	Pop up to count members. Must be greater than 0. Can be given once.

Return value

Case	RESP2	RESP3
Popped	Two-element array: the key, then an array of [member, score] pairs (score as a bulk string)	Same shape, with each score a double
All keys missing or empty	Nil array	Null

The pairs are nested under both protocols.

Errors:

• ERR numkeys should be greater than 0 if numkeys is not a positive integer.
• ERR syntax error if fewer keys follow than numkeys says, the direction is missing or not MIN/MAX, or COUNT is repeated or unknown words follow.
• ERR count should be greater than 0 if count is not a positive integer.
• WRONGTYPE if a key reached before the first non-empty sorted set holds a value that is not a sorted set (a plain set counts as the wrong type here).

Examples

127.0.0.1:6379> ZADD tasks 3 "low" 1 "urgent" 2 "normal"
(integer) 3
127.0.0.1:6379> ZMPOP 2 nosuchkey tasks MIN COUNT 2
1) "tasks"
2) 1) 1) "urgent"
      2) "1"
   2) 1) "normal"
      2) "2"
127.0.0.1:6379> ZMPOP 1 nosuchkey MAX
(nil)

Compatibility

Same as Redis 7.4 and Valkey 8.

See also

BZMPOP, ZPOPMIN, ZPOPMAX, LMPOP