The community forums are in BETA and closed to the public.

Is there a limit on the number channels that can be subscribed under the same PubNub API key?

We have a use case where 2 or 3 publishers (enterprise) wants to send messages to many (1000s) subscribers (its customers), but any message sent by a publisher should be received by only one subscriber like on a 1:1 basis. Each subscriber will listen to channel say 'enterprise1_subscribername1'. And enterprise knows the predefined channel to publish and subscribe to have bi-directional messaging channel. 1. Are there any limitations in the PubNub offering?

Some facts about channels and subscribers and such...

  • There are no limits to the number of channels you can use on your key and there is no limit to the number of subscribers on a single channel.
  • You may only publish to one channel at a single time.
  • A single client may only subscribe to 50 channels at one time (with standard Mutliplexing). Using Channel Groups, a single client can subscribe to 10 channels and each channel group may contain up to 2000 channels.
  • There is not any out-of-the-box feature for guaranteeing that one and only one subscriber gets a message - all subscribers of a channel will receive the message. There are more advanced design patterns for using a message queue on your server to do this, but it is outside of what PubNub offers directly.
  • You could have your publisher round robin the publishing to channels that are unique to each subscriber.

Let me know if that is helpful or if you still have more questions.


Comments to this discussion are now closed!