Returns the active channels.
PUBSUB
CHANNELS
[pattern]
Lists the currently active channels.
An active channel is a Pub/Sub channel with one or more subscribers (excluding clients subscribed to patterns).
If no pattern
is specified, all the channels are listed,
otherwise if pattern is specified only channels matching the specified
glob-style pattern are listed.
Cluster note: in a Valkey Cluster clients can subscribe to every
node, and can also publish to every other node. The cluster will make
sure that published messages are forwarded as needed. That said,
PUBSUB
’s replies in a cluster only report information from
the node’s Pub/Sub context, rather than the entire cluster.
Array reply: a list of active channels, optionally matching the specified pattern.
O(N) where N is the number of active channels, and assuming constant time pattern matching (relatively short channels and patterns)
@pubsub @slow
PSUBSCRIBE, PUBLISH, PUBSUB, PUBSUB HELP, PUBSUB NUMPAT, PUBSUB NUMSUB, PUBSUB SHARDCHANNELS, PUBSUB SHARDNUMSUB, PUNSUBSCRIBE, SPUBLISH, SSUBSCRIBE, SUBSCRIBE, SUNSUBSCRIBE, UNSUBSCRIBE.