ZPOPMAX - Upstash Documentation

Use ZPOPMAX to remove and return the members with the highest scores in a sorted set.

Without a count one member is returned with its score, and with a count up to that many are removed, ordered from the highest score down. A missing or empty key returns an empty result, and the key is deleted once the last member is popped.

Since the read and the removal are atomic, no two workers can take the same member, which turns a sorted set into a priority queue where the score is the priority. BZPOPMAX is the blocking form.

Syntax#

ZPOPMAX <key> [<count>]

Arguments#

Argument	Required	Repeatable	Description
`<key>`	Yes	No	Redis key targeted by the command.
`<count>`	No	No	Number of members to pop.

Important points#

RESP2 represents floating-point reply values as bulk strings; RESP3 may use native double replies. Client libraries commonly decode either form to a language number.

Response#

The reply reports the result of the operation. Error replies have the same shape in RESP2 and RESP3 and are surfaced as exceptions by the SDKs below.

Protocol	Reply
RESP2	Flat array of alternating members and bulk-string scores
RESP3	Without `<count>`, a two-element array of the member and its double score; with `<count>`, an array of such two-element arrays

Note

Client libraries often decode bulk strings, maps, sets, and numeric strings into language-native values. The table describes the Redis wire reply.

Examples#

TCP examples use the TLS REDIS_URL from the Upstash console. REST examples use UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.

Redis CLI

ZPOPMAX my-key

@upstash/redis

import { Redis } from "@upstash/redis";const redis = Redis.fromEnv();const popped = await redis.zpopmax("key", 4);

upstash_redis

from upstash_redis import Redisredis = Redis.from_env()result = redis.zpopmax("my-key")print(result)

ioredis

import Redis from "ioredis";const redis = new Redis(process.env.REDIS_URL!);const result = await redis.zpopmax("my-key");console.log(result);

node-redis

import { createClient } from "redis";const client = await createClient({ url: process.env.REDIS_URL })  .on("error", console.error)  .connect();const result = await client.zPopMax("my-key");console.log(result);

redis-py

import osimport redisclient = redis.from_url(os.environ["REDIS_URL"])result = client.zpopmax("my-key")print(result)

go-redis

package mainimport (    "context"    "fmt"    "os"    "github.com/redis/go-redis/v9")func main() {    opts, err := redis.ParseURL(os.Getenv("REDIS_URL"))    if err != nil {        panic(err)    }    client := redis.NewClient(opts)    result, err := client.ZPopMax(context.Background(), "my-key").Result()    if err != nil {        panic(err)    }    fmt.Println(result)}

jedis

import java.net.URI;import redis.clients.jedis.Jedis;try (Jedis jedis = new Jedis(new URI(System.getenv("REDIS_URL")))) {  Object result = jedis.zpopmax("my-key");  System.out.println(result);}

redis-rs

use redis::TypedCommands;fn main() -> redis::RedisResult<()> {    let url = std::env::var("REDIS_URL").expect("REDIS_URL is not set");    let client = redis::Client::open(url)?;    let mut connection = client.get_connection()?;    let result = connection.zpopmax("my-key", 1)?;    println!("{result:?}");    Ok(())}