You have smart devices deployed all over your IoT solution.
You need to monitor their operation health.
You experience that some of the downstream devices have connectivity issues from time to time.
You know that the $edgeHub's metadata contains health and connectivity information, therefore you start investigating the module twin of the device's edgeHub and here is what you see:
{ "deviceId": "Windows109", "moduleId": "$edgeHub", "etag": "AAAAAAAAAAU=", "deviceEtag": "NzgwNjA1MDU2", "status": "enabled", "statusUpdateTime": "0001-01-01T00:00:00Z", "connectionState": "Disconnected", "lastActivityTime": "0001-01-01T00:00:00Z", "cloudToDeviceMessageCount": 0, "authenticationType": "sas", "x509Thumbprint": { "primaryThumbprint": null, "secondaryThumbprint": null }, "version": 102, "properties": { "desired": { "···" }, "reported": { "schemaVersion": "1.0", "version": { "···" }, "lastDesiredVersion": 5, "lastDesiredStatus": { "···" }, "clients": { "Windows109/SimulatedTemperatureSensor": { "status": "Disconnected", "lastConnectedTimeUtc": "2020-04-08T21:42:42.1743956Z", "lastDisconnectedTimeUtc": "2020-04-09T07:02:42.1398325Z" } }, "$metadata": { "···" }, "$version": 97 } } } Does it help you investigate the problem?
Click on the arrows to vote for the correct answer
A. B.Correct Answer: A.
Option A is CORRECT because the edgeHub module twin's metadata section contains information about the connectivity status of the module.
Here, you can see “connectionState”: “Disconnected”, which can be a good starting point for a deeper investigation.
Option B is incorrect because the edgeHub is the central communication point for the edge's connected child devices, therefore, it is a good starting point when you experience issues with the data flows from the field.
Reference:
Yes, the module twin of the $edgeHub device can help investigate the problem of the downstream device's connectivity issues.
The module twin of the $edgeHub device contains metadata information about the device and its connected devices. In the provided module twin, we can see that the "connectionState" property is set to "Disconnected". This means that the edgeHub device is currently not connected to the Azure IoT Hub.
Furthermore, the module twin contains a "reported" property, which includes a "clients" object. This object provides information about the devices connected to the $edgeHub device. In this case, we can see that the device "Windows109/SimulatedTemperatureSensor" has a "status" of "Disconnected". This suggests that the downstream device may be experiencing connectivity issues.
In addition, we can see that the "lastConnectedTimeUtc" and "lastDisconnectedTimeUtc" properties are populated for the "Windows109/SimulatedTemperatureSensor" device. These timestamps can provide useful information about when the device was last connected or disconnected from the $edgeHub.
Therefore, by examining the module twin of the $edgeHub device, we can gain insight into the connectivity status of downstream devices, such as the "Windows109/SimulatedTemperatureSensor" device, and identify any potential connectivity issues.