Can not provision devices with DPS to one iot hub but other works fine

Hi @Sander van de Velde ,
Thank you for your response.

I figured out that I had to remove the existing link to my iot hub (the one taht failed) and just recreate the link, after thsi is all worked fine.

I know that, before this happened, the iot-hub was touched by terraform but there should have been no active re-deployment nor variable changes that happened. Anyways, I'm happy that I was able ti find and resolve the issue.

To provide you with some answers to the question anyways:

Can you ping the IoT Hubs from your device/network?
Yes, the network appeared all fine

Can you connect to the IoT Hub directly without DPS in between?
I didn't try that

What kind of enrollment do you use?
individual

What allocation policy do you use?
static

What region do you use?
West US 2

Are there any private network or ip address restrictions?
No

Hello Ron Eggler,

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that you are unable to provision devices with DPS to one IoT Hub but other works fine.

The error message indicates that the Query Status operation returned a failed registration status with a status code of 200. This suggests that while the HTTP request was successful, the registration process itself encountered an issue. The ClientError: Unexpected failure further indicates that the client did not anticipate this specific failure mode.

To address this issue, follow these steps:

1. Ensure the enrollment configuration is correct, including verifying X.509 certificates and other settings.
2. Confirm the linkage between DPS and the IoT hub is correctly configured.
3. Use the DPS registration status lookup API to get detailed insights into the registration status.
4. Implement a retry mechanism with exponential backoff to handle transient issues.
5. Ensure the DPS instance is not being throttled, especially if provisioning a large number of devices.
6. Use Azure Monitor to review logs and metrics for both DPS and the IoT hub to identify any underlying issues.
7. Ensure you are using the latest version of the Azure IoT SDKs to avoid issues caused by bugs in older versions.

While the above steps cover many important aspects, consider the following additional points:

• Ensure there are no network issues between the device and the DPS/IoT hub, as network instability can cause intermittent failures.
• Verify that the device twin configuration is correct and consistent across IoT hubs.
• Ensure the device has the necessary permissions to access the IoT hub and DPS.
• Enhance the script to log detailed error messages and stack traces for better troubleshooting.

The below is an updated version of the script with enhanced logging and additional checks:

import asyncio
import logging
from azure.iot.device.aio import ProvisioningDeviceClient
from azure.iot.device.exceptions import ClientError, ServiceError
logging.basicConfig(level=logging.INFO)
async def main():
    provisioning_device_client = ProvisioningDeviceClient.create_from_x509_certificate(
        provisioning_host="your-dps-endpoint",
        registration_id="your-registration-id",
        id_scope="your-id-scope",
        x509=your_x509
    )
    retry_attempts = 3
    for attempt in range(retry_attempts):
        try:
            registration_result = await provisioning_device_client.register()
            logging.info("Registration succeeded")
            break
        except ServiceError as e:
            logging.error(f"ServiceError on attempt {attempt + 1}: {e}")
            if attempt < retry_attempts - 1:
                await asyncio.sleep(2 ** attempt)  # Exponential backoff
            else:
                logging.error("All retry attempts failed")
                raise
        except ClientError as e:
            logging.error(f"ClientError on attempt {attempt + 1}: {e}")
            raise
if __name__ == "__main__":
    asyncio.run(main())

I hope this is helpful! Do not hesitate to let me know if you have any other questions.

Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful.