Azure: Non-epoch Receiver Not Allowed Error
One of the most important tasks in working with Azure IoT Hubs is monitoring messages going to an IoT Hub. To accomplish the task, use a tool such as the Azure CLI with the Azure IoT extension or DeviceExplorer from within Microsoft Visual Studio Code. For information about the Azure IoT extension for the Azure CLI, refer to the Microsoft article,
Microsoft Azure extension for Azure CLI.
When you run your monitoring tool, you may see the following error:
Monitoring events from all devices . . .
Error: At least one receiver for the endpoint is created with epoch of '1', and
so non-epoch receiver is not allowed. Either reconnect with a higher epoch, or
make sure all epoch receivers are closed or disconnected.
In this example, the critical part of the error is shown in this font.
Cause
Microsoft Azure event hubs such as an Azure IoT Hub, enable their publish/subscribe mechanisms using consumer groups. As stated in
Step 1. Create and Configure Items in Azure IoT, Microsoft recommends creating your own consumer groups rather than using the default consumer group. It is best practice to have one consumer per consumer group. When you connect a monitoring tool using the $Default consumer group, you create a conflict with the ThingWorx Azure IoT Hub Connector, which results in the error.
Solution
To resolve the error, use an existing consumer group for the hub or create a new consumer group. To see the consumer groups defined for the Events endpoint on an Azure IoT Hub:
1. Navigate to the blade for your hub.
2. Navigate to > , as indicated here:
3. Under Events, you will see a list of existing consumer groups, as shown here in the lower right side of the screen:
4. At this point, you can either use an existing consumer group, other than $Default, or create a new one. To create a new consumer group, type a name into the text box below the existing consumer groups.
5. To test the solution, run your monitoring tool. You should see JSON messages streaming by. For example, using the Azure CLI with the Azure IoT extension, enter the command to monitor events and specify a consumer group name other than $Default:
az iot hub monitor-events --login "HostName=<url>;SharedAccessKeyName=iothubowner;
SharedAccessKey=<access-key>" --consumer-group "thingworx-azure-iot"