[Other] New pluging: Khepri message store for MQTT retained messages

[NicolasFloquet]

Community Support Policy

• I have read RabbitMQ's Community Support Policy

RabbitMQ version used

4.1.x

How is RabbitMQ deployed?

Community Docker image

Steps to reproduce the behavior in question

Hi!

I'm not sure this is the right place, but I'm currently developping and maintaining a new plugin that allows to use Khepri as a message store of MQTT Retained messages: https://github.com/NicolasFloquet/rabbitmq-mqtt-retained-msg-khepri

The goal is to provide a standalone solution for retained message distribution on clustered RabbitMQ setup.

Since I'm far from being an erlang expert, any review feedback is welcome!

Thanks

[michaelklishin]

It's perfectly fine to announce a plugin like that here on Discussions. Nice!

[michaelklishin]

@NicolasFloquet one important limitation of Khepri for a plugin like this will be the fact that Khepri stores the entire data set in memory in addition to storing it on disk (as Raft requires its implementations to do).

In many cases that won't be a problem in practice because the retained message data set will be small but it's a limitation you should be aware of and perhaps you should document.