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BLMPOP

Syntax text Syntax diagram API methods

BLMPOP timeout numkeys key [key ...] <LEFT | RIGHT> [COUNT count]

Client:

blmpop(
    timeout: float,
    numkeys: int,
    *args: str,
    direction: str,
    count: Optional[int] = 1
) → Optional[list]

Possible errors

ERR value is not an integer: ResponseError
ERR syntax error: ResponseError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: number | string,
    numkeys: number | string,
    ...keys: RedisKey[],
    left: "LEFT",
    callback: Callback<[key: string, members: string[]] | null>
) → Result<[key: string, members: string[]] | null, Context>

blmpop(
    timeout: number | string,
    numkeys: number | string,
    keys: RedisKey[],
    left: "LEFT",
    callback: Callback<[key: string, members: string[]] | null>
) → Result<[key: string, members: string[]] | null, Context>

blmpop(
    timeout: number | string,
    numkeys: number | string,
    ...keys: RedisKey[],
    left: "LEFT"
) → Result<[key: string, members: string[]] | null, Context>

blmpop(
    timeout: number | string,
    numkeys: number | string,
    keys: RedisKey[],
    left: "LEFT"
) → Result<[key: string, members: string[]] | null, Context>

blmpop(
    timeout: number | string,
    numkeys: number | string,
    ...keys: RedisKey[],
    left: "LEFT",
    countToken: "COUNT",
    count: number | string,
    callback: Callback<[key: string, members: string[]] | null>
) → Result<[key: string, members: string[]] | null, Context>

Possible errors

ERR value is not an integer: ReplyError
ERR syntax error: ReplyError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: double,  // seconds to block. A timeout of zero can be used to block indefinitely.
    direction: ListDirection,
    keys: String...
) → KeyValue<String, List<String>>  // The element being popped and pushed

blmpop(
    timeout: double,  // seconds to block. A timeout of zero can be used to block indefinitely.
    direction: ListDirection,
    count: int,
    keys: String...
) → KeyValue<String, List<String>>  // The element being popped and pushed

blmpop(
    timeout: double,  // seconds to block. A timeout of zero can be used to block indefinitely.
    direction: ListDirection,
    keys: String...
) → KeyValue<String, List<String>>  // The element being popped and pushed

blmpop(
    timeout: double,  // seconds to block. A timeout of zero can be used to block indefinitely.
    direction: ListDirection,
    count: int,
    keys: String...
) → KeyValue<String, List<String>>  // The element being popped and pushed

Possible errors

ERR value is not an integer: JedisDataException
ERR syntax error: JedisDataException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: long,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → KeyValue<K, List<V>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

blmpop(
    timeout: double,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → KeyValue<K, List<V>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

Possible errors

ERR value is not an integer: RedisCommandExecutionException
ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: long,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → RedisFuture<KeyValue<K, List<V>>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

blmpop(
    timeout: double,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → RedisFuture<KeyValue<K, List<V>>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

Possible errors

ERR value is not an integer: RedisCommandExecutionException
ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: long,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → Mono<KeyValue<K, List<V>>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

blmpop(
    timeout: double,  // the timeout in seconds.
    args: LMPopArgs,  // the additional command arguments.
    keys: K...  // the keys.
) → Mono<KeyValue<K, List<V>>>  // KeyValue&lt;K,V&gt; array-reply specifically. null when key does not exist or the timeout was exceeded. @since 6.2

Possible errors

ERR value is not an integer: RedisCommandExecutionException
ERR syntax error: RedisCommandExecutionException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

BLMPop(
    ctx: context.Context,
    timeout: time.Duration,
    direction: string,
    count: int64,
    keys: ...string
) → *KeyValuesCmd

Possible errors

ERR value is not an integer: redis.Error
ERR syntax error: redis.Error

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

BLMPop(
    timeout: double,
    keys: RedisKey[],
    listSide: ListSide,
    count: long?
) → Tuple<RedisKey, List<RedisValue>>?

BLMPop(
    timeout: double,
    key: RedisKey,
    listSide: ListSide,
    count: long?
) → Tuple<RedisKey, List<RedisValue>>?

BLMPop(
    db: Any,
    timeout: Any,
    [key]: Any,
    listSide: Any,
    count: Any
) → return

Possible errors

ERR value is not an integer: RedisServerException
ERR syntax error: RedisServerException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    $timeout: int,
    $keys: array,
    string $modifier = 'left': Any,
    int $count = 1: Any
) → array

Possible errors

ERR value is not an integer: Predis\Response\ServerException
ERR syntax error: Predis\Response\ServerException

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: Float,  // maximum number of seconds to block
    *keys: String, Array<String>,  // one or more keys with lists
    modifier: String,  // LEFT or RIGHT
    count: Integer  // a number of elements to pop
) → Array<String, Array<String>>  // list of popped elements or nil

Possible errors

ERR value is not an integer: Redis::CommandError
ERR syntax error: Redis::CommandError

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: f64,
    numkeys: usize,
    key: K,
    dir: Direction,
    count: usize
) → (Option<[String

Possible errors

ERR value is not an integer: ErrorKind::Server(ServerErrorKind::ResponseError)
ERR syntax error: ErrorKind::Server(ServerErrorKind::ResponseError)

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

blmpop(
    timeout: f64,
    numkeys: usize,
    key: K,
    dir: Direction,
    count: usize
) → (Option<[String

Possible errors

ERR value is not an integer: ErrorKind::Server(ServerErrorKind::ResponseError)
ERR syntax error: ErrorKind::Server(ServerErrorKind::ResponseError)

See Redis error messages for what each error means. Other errors, such as connection errors, aren't listed.

Available since:: Redis Open Source 7.0.0
Time complexity:: O(N+M) where N is the number of provided keys and M is the number of elements returned.
ACL categories:: @write, @list, @slow, @blocking,
Compatibility:: Redis Software and Redis Cloud compatibility

Note:

This command's behavior varies in clustered Redis environments. See the multi-key operations page for more information.

BLMPOP is the blocking variant of LMPOP.

When any of the lists contains elements, this command behaves exactly like LMPOP. When used inside a MULTI/EXEC block or a Lua script, this command behaves exactly like LMPOP. When all lists are empty, Redis will block the connection until another client pushes to it or until the timeout (a double value specifying the maximum number of seconds to block) elapses. A timeout of zero can be used to block indefinitely.

See LMPOP for more information.

Required arguments

timeout

The maximum time to block, in seconds. A timeout of 0 blocks indefinitely.

numkeys

The number of keys that follow.

key [key ...]

One or more keys of lists to operate on.

LEFT | RIGHT

The end of the list to pop elements from: LEFT (head) or RIGHT (tail).

Optional arguments

COUNT count

The number of elements to pop. Defaults to 1.

Redis Software and Redis Cloud compatibility

Redis Software	Redis Cloud	Notes
✅ Standard ✅ Active-Active	✅ Standard ✅ Active-Active

Return information

RESP2 RESP3

One of the following:

Nil reply: when no element could be popped and the timeout is reached.
Array reply: a two-element array with the first element being the name of the key from which elements were popped, and the second element being an array of the popped elements.