BLMPOP

{{< note >}} This command's behavior varies in clustered Redis environments. See the [multi-key operations]({{< relref "/develop/using-commands/multi-key-operations" >}}) page for more information. {{< /note >}}

BLMPOP is the blocking variant of [LMPOP]({{< relref "/commands/lmpop" >}}).

When any of the lists contains elements, this command behaves exactly like [LMPOP]({{< relref "/commands/lmpop" >}}). When used inside a [MULTI]({{< relref "/commands/multi" >}})/[EXEC]({{< relref "/commands/exec" >}}) block or a Lua script, this command behaves exactly like [LMPOP]({{< relref "/commands/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]({{< relref "/commands/lmpop" >}}) for more information.

Redis Software and Redis Cloud compatibility

| Redis Software | Redis Cloud | <span style="min-width: 9em; display: table-cell">Notes</span> | |:----------------------|:-----------------|:------| | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | <span title="Supported">✅ Standard</span> <span title="Supported"><nobr>✅ Active-Active</nobr></span> | |

Return information

{{< multitabs id="blmpop-return-info" tab1="RESP2" tab2="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.

-tab-sep-

One of the following:

• Null 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.

{{< /multitabs >}}