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Hi,
I'm currently doing some testing forwarding telemetry from two devices into IoT Central. Both devices are using node-red with the 'node-red-contrib-azure-iot-device' node, using different device IDs to forward messages onto IoT Central with identical node-red flows.
I've debugged within node-red and can see that messages are sent through every 5 minutes and are not duplicating. However, after some time IoT Central begins to duplicate messages in the raw data from one of the devices and not the other, starting with 2 messages, all the way up to 10+ duplicate messages.
Initially I thought it might be the IoT node but the issue doesn't occur on the other device with the same flow setup. Then I thought it might be a problem with the device, but I can see the messages coming through to the IoT node are never duplicated. To simplify I am just forwarding a debug message to IoT Central and can see it starts to duplicate after some time:
What can cause duplication of messages within Central? Where can I debug this issue within Central or perhaps Centrals IoT Hub?
Many thanks in advance for any help given
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Hello @RossIoT Thanks for waiting on this query,
I am following up on the issue, please let us know if you need further help in this matter and we would be happy to help further.
Hello @RossIoT thanks for waiting on this issue, could you please confirm if you have submitted any support ticket on this issue ? we would be happy to assist you with a support ticket in case/
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Can you share any more details of the flow you're using - in particular how are you generating the _eventcreationtime value?
About how long does it take for the duplication to appear?
Thanks for the quick response,
msg = {
'topic': 'telemetry',
'payload': {
"debug": "message"
},
'properties': [
{'key': 'iothub-creation-time-utc', 'value': new Date().toISOString()}
]
}
return msg;
It takes around 4 hours for the duplication to start appearing in IoT Central
One more question - are the two flows running in the same Node RED environment, or are they completely separate?
They're in separate environments
I tried running a similar setup, but didn't see any message duplication appear.