AWS IoT MQTT disconnect while awaiting acknowledgement

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

matty — Wed, 26 Apr 2023 16:00:27 GMT

This seems to have been cleared up by using Toolchain Manager v1.2.4 to uninstall/remove nRF Connect SDK v2.0.0 and any other versions installed on the system and using the Extensions command in VS Code to uninstall nRF Connect for VS Code Package. Then, using Toolchain Manager v1.2.4 to install nRF Connect SDK v2.0.0 and then using the Open VS Code button in Toolchain Manager to get nRF Connect for VS Code back in place. Thank you for your help.

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

matty — Fri, 21 Apr 2023 13:11:16 GMT

I created my AWS "Thing" without Device Shadow. In the AWS IoT console under Manage->Things->my_thing, Device Shadow is zero.

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

JyriLehtinen — Fri, 21 Apr 2023 12:19:42 GMT

The aws_iot_send uses Zephyr native mqtt_publish() which is non blocking I believe. Successful return does not guarantee that the message was successfully sent or received, I think it returns after it's been written to the socket or, if an error occurred before that (e.g client state was disconnected before the mqtt_publish() call).

I just saw a bit similar behaviour with one of our demo devices, it started disconnecting from AWS with the reason CONNECTION_LOST, and this happening as it was receiving and updating the Thing Shadow. Are you able to delete the Thing Shadow from the AWS-side?

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

matty — Fri, 21 Apr 2023 12:06:27 GMT

I am setting the qos member of the aws_iot_data structure to MQTT_QOS_1_AT_LEAST_ONCE.

I expect to get a AWS_IOT_EVT_PUBACK event in the callback function I provided when I aws_iot_init not a AWS_IOT_EVT_DISCONNECTED.

My app has three large buffers to send. It tries an aws_iot_send with the first and if successful will move on to the next and so on. I have tried a .qos of MQTT_QOS_0_AT_MOST_ONCE, and not waited on an acknowledgement/PUBACK. In this scenario, while the aws_iot_send returns successfully the first and second time, the AWS_IOT_EVT_DISCONNECTED happens before the third buffer and that one naturally fails since the socket isn't connected.

For my app, the AWS_IOT_EVT_DISCONNECTED always occurs 2 to 3 seconds after the first aws_iot_send.

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

matty — Fri, 21 Apr 2023 11:44:35 GMT

The Modem firmware is 1.3.4

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

JyriLehtinen — Fri, 21 Apr 2023 11:17:49 GMT

The message id is set by pseudorandom, get_sys_tick_u32() or something like that by the aws_iot library, unless set manually. The two messages listed there are separate messages. If sent with QoS 1 you should be getting PUBACK for those same ID's if it's successfully received by the broker.

Have you checked that you're sending with QoS 1 or 2? PUBACK won't be sent for QoS 0

RE: AWS IoT MQTT disconnect while awaiting acknowledgement

Hakon — Fri, 21 Apr 2023 10:33:25 GMT

Hello,

what modem firmware are you running?