MQTT5 persistent session examples

[golkedj]

I'm currently leveraging aiomqtt 2.3.2 in combination with AWS IoT MQTT and I'm trying to get persistent sessions on my clients working.

I have the following client initiation code:

        tls_params = aiomqtt.TLSParameters(
            ca_certs=self._config["ca_file"],
            certfile=self._config["cert_file"],
            keyfile=self._config["key_file"],
            tls_version=ssl.PROTOCOL_TLSv1_2,
        )

        _properties = paho.mqtt.properties.Properties(PacketTypes.CONNECT)
        _properties.SessionExpiryInterval = 60 * 60 * 24

        self._client = aiomqtt.Client(
            hostname=self._config["endpoint"],
            port=self._config["port"],
            tls_params=tls_params,
            identifier=self._config["client_id"],
            protocol=aiomqtt.ProtocolVersion.V5,
            keepalive=60,
            clean_start=False,
            properties=_properties,
        )

Per the MQTT documentation it would seem that I need to set clean_start to False and set a SessionExpiryInterval. I set the session expiry interval per #233 and #277, but it doesn't seem to pick up messages missed while offline with these settings. Is there any more information on how to do persistent sessions with this package with MQTT5?

[empicano]

Hey there, sorry for the late reply! Yes, clean start set to False and SessionExpiryInterval to something high (you can set it to 2**32 - 1 to never let the session expire) sounds good.

You're probably aware, but just to be sure: The brokers usually only keep QoS >= 1 messages.

Did you try reproducing the issue with a different broker (e.g. mosquitto) to make sure that it's independent from AWS?