Persistent Session for EMQX 5.1 and above is missing in documentation

Hi Everyone,

Sorry to repost this topic, I am currently using EMQX broker 5.0.22 for testing our IOT devices using docker-compose deployment and I thought of upgrading the broker to 5.1. Unfortunately I couldn’t find the Persistent Session topic in the Configuration manual. The EMQX broker (5.1) now does not persist the subscribers sessions if we restart the broker. I was wondering is the Persistent Session is now removed completely or is it now handled differently.

If it is handled differently where can I find the config parameters in the configuration manual. Can someone please guide here?

I thought this is a function of the client when the connection is established. Have you read this MQTT Persistent Session and Clean Session Explained | EMQ

Yes, I agree. Also the client is implemented as described When ever the emqx 5.0.22 container is restarted, all the client were able to receive the messages without re-subscribing to the topics.

Now in 5.1.x version, the clients need to be resubscribed as well (technically restarting the clients). We wanted to avoid the resubscribing to the topics if the emqx container is restarted.


The implementation of persistent session that was delivered in 5.0 was experimental and we ended up axing it, because it wouldn’t scale well enough. We’ve been working on a new implementation. Currently it’s undergoing performance benchmarking stage. If tests work out well, the preview of the feature will be included in 5.4.