4 ms·
One of the best features of MQTT that is often overlooked is that the topics are created on the fly and also destroyed on the fly. The protocol does not require
by bdamm 7y ago
One of the best features of MQTT that is often overlooked is that the topics are created on the fly and also destroyed on the fly. The protocol does not require the server to maintain topics lists (assuming no retained messages). The server therefore scales based on the throughput and the number of clients (and their subscriptions) but not the size of the topic tree. The topic tree designer is therefore free to use enormous topic spaces with billions of topics if they so desire.
- Arnavion 7y agoIt's also a bad feature for bandwidth-constrained or low-power devices since it requires sending the whole topic string with every message. That's why MQTT-SN, and now MQTT 5, allow registering a topic string -> smaller ID mapping and then using the ID for messages at the expense of persistent state on both ends.
- bdamm 7y agoI've avoided MQTT-SN (and consequently have limited MQTT to high power segments of our stack, yes a phone is high power) due to lack of robust implementations. If that changes then I'd reconsider.
- rndmio 7y agoIf you follow the minutes of the MQTT TC at OASIS, after the release of MQTT v5 there is now talk of formalising the MQTT-SN spec in a similar fashion, that should lead (in time) to more robust implementations.