Thanks very much Piyush, will try your suggestion

Thanks for the detailed reply Piyush.

I think there are two separate issues here relating to reducing the WAN traffic for device metric updates

1. Whether it is technically feasible
2. Whether there is a valid business case

The business case is clear because for IoT in the field, eg agricultural ...

As I currently understand it, Rainmaker devices transmit MQTT messages to AWS on a single topic, using JSON in the payload to distinguish the particular updated parameters.

If I'm right, then it leads to a >10x increase in the data usage for the device, compared with using the MQTT topic to ...

Thank you Piyush. I have done as you suggested and it seems to me that Rainmaker is not using MQTT very efficiently.

As an example, say I want to send battery voltage = 12V

Rainmaker publishes the following to MQTT
topic: $aws/rules/esp_set_params/node/F412FA68E350/params/local,
data: {"Battery ...

I am having unreliable OTA updates on an otherwise reliable link, immediately after system reset.

Specifically I get
I (34524) heap_metrics: free:0xca64 lfb:0x4000 min_free_ever:0x2718
I (34525) heap: alloc_fail size:0x416d func:heap_caps_calloc
E (34525) Dynamic Impl: alloc(16749 bytes) failed ...

Thank you Piyush, I'll do that

Thank you.

Which of the commands below allows me to do that?
\usage: esp-rainmaker-cli [-h]
{configure,signup,login,logout,forgotpassword,getnodes,getnodeconfig,getnodestatus,setparams,getparams,removenode,provision,getmqtthost,claim,test,otaupgrade,getuserinfo,sharing,create_cmd_request,get_cmd ...

Is there a way to view the MQTT messages sent by the node and received by the Rainmaker broker during development?