You are operating an IoT solution which collects sensor data from a wide range of field devices, including speed sensors, cameras etc.
The devices are connected to an S2 hub.
In order to prevent data loss and throttling, you want to set up alerts to warn you when the message throughputfor the last 1 minute period exceeds the 80% of the throttle threshold.
Which metric alert should you set up in your IoT Hub?
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer: B.
Option A is incorrectbecause for S2 hubs, the flow of device-to-cloud messages will be automatically throttled when the flow rate reaches 120 messages/s/unit.
Setting the threshold value to 10 000 (i.e.
160 messages/s ) will not prevent throttling.
Option B is CORRECTbecause for S2 IoT hubs, the number of device-to-cloud messages is limited to 120/sec/unit.
It means that at this rate the automatic throttling takes effect.
In order to fulfil the requirement, you need to use the Telemetry messages sent metric to 6 000 messages per minute (i.e.
100 messages/s, close to the 80% of the threshold value).
Option C is incorrect because the throttling logic is triggered by the number of messages successfully sent to the IoT Hub, which is measured by the Telemetry messages sent metric.
Option D is incorrect because the Total number of messages used metric is related to the quotas.
It is the aggregate number of messages you can send in your hub per day.
It is not suitable for monitoring the send rate of the message flow.
References:
The correct answer to this question is B. Telemetry messages sent > 6000 / min.
When using Azure IoT Hub to collect data from a large number of field devices, it is important to monitor the message throughput to prevent data loss and throttling. To set up alerts for this, you need to choose a metric that will accurately reflect the message throughput for the last 1 minute period and that will trigger an alert when the throughput exceeds 80% of the throttle threshold.
In this case, the best metric to use is "Telemetry messages sent". This metric reflects the number of telemetry messages that have been successfully sent to IoT Hub from the devices. By setting the alert threshold to 6000 messages per minute, you can monitor the message throughput for the last 1 minute period. If the number of messages sent exceeds 80% of the throttle threshold, an alert will be triggered, allowing you to take appropriate action to prevent data loss and throttling.
Option A, "Telemetry messages sent > 10000 / min", is too high and would not allow you to detect when the message throughput is approaching the throttle threshold.
Option C, "Telemetry message send attempts > 10000 / min", is not an accurate reflection of the message throughput, as it includes messages that were not successfully sent to IoT Hub.
Option D, "Total number of messages used > 6000 / min", is not a metric that is available in Azure IoT Hub and is therefore not a valid answer.