CODEWITHSUNDEEP
azure-iot-hubazure-stream-analytics
Govind
Govind

Reputation: 31

How to read IoT Hub message 'application properties' in Stream Analytics?

I have enriched the IoT Hub message based on Microsoft documentation and routing it to the built-in endpoint, and then having Stream Analytics access the messages by providing IoT Hub as the input to it.

IoT Hub message enrichment adds the enrichment data to the application properties of the message and not the body itself, so I'm having challenges trying to get that enrichment data from Stream Analytics - as the output of Stream Analytics is the Blob and it only contains the actual message I sent to IoT Hub.

Enrichment data here refers to certain data (like location, identity, etc.) that I'm mapping to the devices registered in IoT Hub based on device-twin properties.

I have tried the steps mentioned in GetMetadataPropertyValue and parsing JSON in Stream Analytics, but no luck in terms of getting the 'application properties' from Stream Analytics directly.

Could someone help me figure out how to access the application properties from Stream Analytics or at least point to the right resources?

Thank you.

Upvotes: 3

Views: 1947

Answers (2)

Roman Kiss
Roman Kiss

Reputation: 8245

try the following in your query:

GetMetadataPropertyValue(iothub, '[User]') as userprops

your enrichment data will be in the userprops.

Example:

device telemetry data:

{"counter":29,"time":"2019-08-08T13:42:26.1517415Z","deviceId":"device1","windSpeed":8.2023,"temperature":16.06,"humidity":79.46}

publishing on topic:

devices/device1/messages/events/$.ct=application%2Fjson&$.ce=utf-8&abcd=1234567

IoT Hub Enrich messages: enter image description here

ASA job:

select 
    *,
    GetMetadataPropertyValue(iothub, '[User]') as userprops 
into
    outAF
from 
    iothub

Output on the Azure Function (outAF):

[
  {
    "counter": 29,
    "time": "2019-08-08T13:42:26.1517415Z",
    "deviceId": "device1",
    "windSpeed": 8.2023,
    "temperature": 16.06,
    "humidity": 79.46,
    "EventProcessedUtcTime": "2019-08-08T13:42:25.7495769Z",
    "PartitionId": 1,
    "EventEnqueuedUtcTime": "2019-08-08T13:42:25.568Z",
    "IoTHub": {
      "MessageId": null,
      "CorrelationId": null,
      "ConnectionDeviceId": "device1",
      "ConnectionDeviceGenerationId": "636842046144267242",
      "EnqueuedTime": "2019-08-08T13:42:25.363Z",
      "StreamId": null
    },
    "User": {
      "abcd": "1234567",
      "status": "inprocess",
      "version": "42"
    },
    "userprops": {
      "abcd": "1234567",
      "status": "inprocess",
      "version": "42"
    }
  }
]

The following screen snippet shows an event message from a second custom endpoint for enrich messages such as the EventGrid:

{
  "id": "b983e8bf-88b5-cac3-9370-2c64037b2f1c",
  "topic": "/SUBSCRIPTIONS/00000000-0000-0000-0000-000000000000/RESOURCEGROUPS/myRG/PROVIDERS/MICROSOFT.DEVICES/IOTHUBS/myIOT",
  "subject": "devices/device1",
  "eventType": "Microsoft.Devices.DeviceTelemetry",
  "eventTime": "2019-08-08T13:42:25.363Z",
  "data": {
    "properties": {
      "abcd": "1234567",
      "status": "inprocess",
      "version": "42"
    },
    "systemProperties": {
      "iothub-content-type": "application/json",
      "iothub-content-encoding": "utf-8",
      "iothub-connection-device-id": "device1",
      "iothub-connection-auth-method": "{\"scope\":\"device\",\"type\":\"sas\",\"issuer\":\"iothub\",\"acceptingIpFilterRule\":null}",
      "iothub-connection-auth-generation-id": "636842046144267242",
      "iothub-enqueuedtime": "2019-08-08T13:42:25.363Z",
      "iothub-message-source": "Telemetry"
    },
    "body": {
      "counter": 29,
      "time": "2019-08-08T13:42:26.1517415Z",
      "deviceId": "device1",
      "windSpeed": 8.2023,
      "temperature": 16.06,
      "humidity": 79.46
    }
  },
  "dataVersion": "",
  "metadataVersion": "1"
}

Upvotes: 3

Zainu
Zainu

Reputation: 120

Did you check GetRecordPropertyValue as explained here http://learniotwithzain.com/2019/08/alert-engine-using-azure-stream-analytics-and-sql-azure-as-reference-data/

Upvotes: 0

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