Dear HiveMQ community,
I am new to MQTT protocol and HiveMQ. For the time being, I have been developing a Java implementation of the Meross IoT library. The Meross broker seems to be based on Amazon AWS MQTT tecnology. I went with MQTT 3 as I have no clues about MQTTT 5 support by the Meross broker.
As far as the HTTP part everything is working ok, i.e. It is possible to retrieve the cloud credentials and the devList as well. I have chosen HiveMQ to implement the MQTT functionality. as is it is relaiable and encloses many features. The MQTT 3 implementation returns a connAck of “SUCCESS” and TLS handshaking performs correctly too but when subscribing to the topic filter the suback returns the following exception:” com.hivemq.client.mqtt.mqtt3.exceptions.Mqtt3SubAckException: SUBACK contains only Error Codes”
Here is other Himemq relevant log information:
18:36:10.424 DEBUG [vemq.client.mqtt-1-1] [o.netty.handler.ssl.SslHandler:1930 ] - [id: 0xb5028347, L:/168.192.1.154:54210 - R:mqtt-eu-5.meross.com/34.251.5.126:443] HANDSHAKEN: protocol:TLSv1.2 cipher suite:TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
18:36:10.537 DEBUG [main] [munication.MerossMqttConnector:72 ] - published message: MqttPublish{topic=/appliance/2306066404030351200248e1e9c96ff1/subscribe, payload=44byte, qos=AT_LEAST_ONCE, retain=false}
18:36:10.538 DEBUG [main ] [munication.MerossMqttConnector:73 ] - connAck: MqttConnAck{returnCode=SUCCESS, sessionPresent=false}
Based on what I’ve read on HiveMQ docs this kind of error might be related to the topic subscription phase so I checked whether the topicfilter and the topic are correctly formed:
18:47:27.049 INFO [main ] [TestMerossMqttConnector :18 ] - Response Topic:/app/3807527-06df42eed27d14714ab47739fb2d7730/subscribe
18:47:27.066 INFO [main ] [TestMerossMqttConnector :25 ] - Publish Topic:/appliance/2306066404030351200248e1e9c96ff1/subscribe
They apperars to be correctly formed according to the documentation I have got, but I suspect of the publish topic.
How can I investigate on this exception?
How could I find out if the broker supports MQTT5 protocol?
Any suggestion is appreciated, thanks in advance.
P.S. Here is the repo: