Limitations of Publish / Subcribe

Am I correct from reading the Docs that on a single device I can only call Partcle.subscribe() a max of 4 time? If so, would I be able to work around that 4 handler limitation by unsubscribing to some and then subscribe again to others? And do that back and forth?

Also, on the flip-side, are there any limitations to Particle.publish in the same respect I didn’t see it in the Docs but just want to make sure I’m no overlooking it.


That is correct, you can only have 4 subscription handlers. However the eventName string is a prefix - it will match every string that beings with that string, so the usual workaround is to name your events carefully so you can catch all of your events with a single subscription handler.

Another method is to include more information in the data that differentiates what the event is, to reduce the need for separate events.

When you want to publish events to a single device, common technique is to prefix the event name with the deviceID (hex string) of the destination. The device subscribes to that event, and you can also suffix stuff after the deviceID to further differentiate the event.

You could register and unregister handlers, but it’s not very efficient and you could possibly lose events while you were not subscribed, because they’re not queued in the cloud.

The only limitation on publish is that the average cannot exceed 1 event per second. You can burst out 4 events quickly, but then you can’t send any more for 4 seconds. Or you can constantly send out 1 event every second.

That’s per published event, If multiple devices were publishing to a subscription handler it could end up receiving more than 1 event per second.


Thanks Rick! That clears is up quite well. I am good to go now. I’m slowly replacing different devices around my home with one Particle Mesh network using Blynk. So far so good! Good suggestions as well - much appreciated.