In Redis Pub/Sub, we create different Redis channels as per the application requirement. Each application using Redis Pub/Sub will use these channels for either publishing purpose or subscribing purpose.

Whenever any application publishes a message to a channel, all subscriber client applications which have subscribed to that channel will be notified immediately for that message.

Below we know about two important commands used in Redis PUB/SUB implementation.

Command to list all active channels in Redis Pub/Sub

Below command will list out all active channels for connected Redis instance.


Command to list the number of subscribers subscribed to a Redis channel

If you want to know the number of subscribers to a channel, then you can use below command. This will return number of subscribers to a particular channel.