Retanied messages are needed? Side effect.

magcode / daikin-mqtt

MQTT interface for Daikin AC Wifi Adapter

GNU General Public License v3.0

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Retanied messages are needed? Side effect. #6

Closed FulvioSpelta closed 4 years ago

FulvioSpelta commented 4 years ago

I've seen that the messages are published as "retained". IMHO this is not necessary because the "subscriber" will receive:

The LWT (or the last state) message in order to know immediately know the state of the device.
Updated data at the defined interval Furher the "retained" messages could be very old creating noise in the subscriber.

Side effect Every test/device remain in the broker db and is delivered at every connection at every subscriber; in this example i've done a test using ac-room1 deviceid and now every subscribers (different mqtt clientid) receive a full set of data at every connection:

magcode commented 4 years ago

I understood the convention that "retained" is the default https://homieiot.github.io/specification/#qos-and-retained-messages

I'm aware of this effect that test devices stay in the broker. Not sure how to solve it.

FulvioSpelta commented 4 years ago

As the standard is asking for this implementation I suggest to leave it untouched, I'll clean the broker db.

The only concern is about the overall behavior of the gateway: because the "state" miss the LWT message, when a messages consumer connect to the broker it recevive a full set of measure and a "ready" state that will make it consider the gateway to be up&running even if it is completely off or disconnected.

magcode commented 4 years ago

I made retained=false and qos=0 as the default now. You can set it back to retained and qos=1 in the properties file (see readme)