Count total number of messages per project?

Hello @Blazej Marciniak,

welcome to this moderated Azure community forum.

The IoT Hub counts the number of 'messages' per day because it offers a service sized on that number.

If you want to know the number of 'messages' per devices, this is not a feature provided by the IoT Hub.

You need to add extra logic listening to any of the messages coming from the IoT Hub.

For example, Stream analytics is capable of counting the number of messages per time slot, per device (check out the tumbling window).

Regarding the message count difference, did you know the IoT Hub does not actually count the number of incoming messages?

What it counts is the number of chunks, the 4KB parts your incoming message is made of.

An explination of how to measure the size, check out this documentation.

If the incoming message has a size of 5KB, it is counted as two chunks.

This could explain the difference.

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Hi @Blazej Marciniak Greetings! Welcome to Microsoft Q&A forum. Thank you for posting this question here.

The time granularity determines the number of data points that needs to be used by the chart for plotting. Consider the below scenario for example

For time granularity = 30 minutes and the time range = 24 hours:

• The chart is drawn from 48 datapoints. That is 24 hours x 2 datapoints per hour (60min/30min) aggregated
• The line chart connects 48 dots in the chart plot area.
• Depending on whether Aggregation is set to Max/Min/Avg, each datapoint represents the max/min/avg of all messages used during each of the relevant 30-min time periods.

The default time granularity for the graph is 5 minutes and the aggregation is set to Max. If we change the value from default to 1 day, it greatly reduces the sample size for the graph plot and I would expect to see a change in the value rendered. Hope this clarifies your question on why the plot generated differs if the granularity is changed.

perhaps there's an easier way to calculate this

Unfortunately, there is no direct approach provided by IoT Hub that lets you monitor/track the message usage count per device/project level. It would only capture the metric at the IoT Hub level. You would have to do some sort of additional manipulation by routing the telemetry events to a different end point such as Event Hub or Stream Analytics job and capture in the property device-id in the message to perform additional analysis.

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