Unable to receive messages on Google Cloud from client(Thingy91) using MQTT protocol.

[Dheeraj]

Hi,

As per our requirement, we have implemented google cloud wrapper on top of existing MQTT  Ref:(https://github.com/NordicPlayground/fw-nrfconnect-nrf/tree/master/samples/nrf9160/mqtt_simple) in order to send messages (GPS, BLE, etc) to Google cloud in Asset tracker application.

But we could see very weird behavior when the client (Thingy91_PCA20035) sends messages in every 30 minutes of periodic interval, google could never receive any messages and the cloud is unresponsive but, still thingy91 sending messages. No error messages from Cloud or TCP sockets.

NOTE: In 30 mins of gap (Where no messages sending from client to server), we are pinging cloud using mqtt_live() in KEEPALIVE_TIME/3 manner, in order to keep the connection available.

At the same time, if we send messages <= 6 mins periodic interval server able to receive and acknowledge back to the device and no issues seen.

Please kindly help us to get some insights on this.

Thank You

[Simon]

Could you upload a modem trace of the case where you're sending messages every 30 minutes?

Best regards,

Simon