MQTT QoS 1: Retransmission message when no PUBACK is received

[ACuenca]

Hi,

I'm developing an application for nRF9160 that connects to AWS IoT Core using AWS IoT library (of nRF Connect SDK 2.3.0). I want to publish messages with QoS level 1, so, after publishing a message, my code waits until PUBACK is received back.

My question is: what does AWS IoT library do when no PUBACK is received? I want to know if this library republishes the message automatically after a certain time or it doesn't. In case it doesn't, I understand that my code should retransmit the message by itself.

Thanks in advance,

Alejandro Cuenca

[Charlie]

Hi Alejandro,

You are correct.
You need to implement logic on the application level to send again if PUBACK is not received within some user-defined time.

Best regards,

Charlie

[Charlie]

Hi Alejandro,

I found there is a QoS library you can maybe use for it. 
Quality of Service — nRF Connect SDK 2.4.0 documentation (nordicsemi.com)

Best regards,

Charlie