When using DeviceClient I can send messages using SendEvent and files using SendBlob. But I did not find a way to receive acknowledgement that messages/files have been received by Azure IoT Hub?
The only way I found to solve this is using serviceClient.GetFileNotificationReceiver().
Am I missing something or is this the only way?
Also it seems I need SharedAccessKeyName to use ServiceClient. But this is not present in e.g. tokens created by DeviceExplorer (which I use for DeviceClient). Any advice is appreciated.
For Java and C sdks there are IotHubEventCallback and IOTHUB_CLIENT_EVENT_CONFIRMATION_CALLBACK but for C# there is no such interface implemented.
So, for C#, a message will be sent successfully if DeviceClient.SendEventAsync() without throwing any exception, otherwise it fails.
Or you can utilize Event Hub-compatible endpoint to monitor the status of operations on your IoT hub, D2C message, file upload...
For ServiceClient, you need Azure IoT Hub connection string, not device connection string. You can find it in Configuration of Device Explorer:
Related
I'm tryng to develop an high-frequency message dispatching application and i'm observing for the behavior of the SDK about message reading from the ModuleClient connected to the edgeHub by using "MQTT on TCP Only" transport settings.
Seems that there is no way to read multiple messages at time (batch) from the edgeHub (I think is something related to the underlying protocol).
So the result is that one must sequentially read a message, process it and give the ack to the hub.
Does exist a way to process multiple message at time without waiting for the processing of the previous?
Is this "limitation" tied to the underlyng protocol?
I'm using Microsoft.Azure.Devices.Client 1.37.2 on a .NET Core 3.1 application deployed on Azure Kubernetes (AKS) by using Azure IoT Edge on Kubernetes workload.
You are correct, you cannot use batch in MQTT protocol. This is a limitation tied to IoTHub when using MQTT Protocol.
IoT Hub only supports batch send over AMQP and HTTPS at the moment.
The MQTT implementation loops over the batch and sends each message
individually.
Ref: https://github.com/Azure/azure-iot-sdk-csharp
Suggest that you add a new feature request, if need IoTHub to support batch when connecting using MQTT: https://feedback.azure.com/forums/321918-azure-iot-hub-dps-sdks
I have sent messages to Azure IoT Hub device called dev1, I could not see the messages in IoT Hub but, I can read the messages only when the client application is online when the sender is sending messages. Azure IoT Hub supports only online messaging and no offline messaging? If offline message support is there, where are these messages are stored, I couldn't see the messages in IoT Hub.
When I configure the custom endpoint as Blob storage, I can see messages are stored in blobs.
Please help me on this.
Thanks in advance
If I understand correctly you are looking for reading the messages directly on IoT Hub portal UI. If that is the case, then one of the things which you can make sure about D2C Messages in IoT Hub portal (UI perspective) is looking at the Metrics chart (See below Images). For reading the actual payload you have to make use of in-built Event Hub endpoint or routing to other supported endpoints.(You have already mentioned in your scenario-Client/Sender applications, So I think you have already known this method of reading messages)
The Metrics chart atleast tells you that the messages are received in IoT Hub (UI), you can't read them on the Portal(UI).
IoT Hub is built on top of Event Hubs, and that's where your messages will be until you start reading them. They will be stored there for 1 day by default, although you can change that up to 7 days. For more information on retention, please read this page.
Using the azure-iot-sdk for python I have a program that opens a connection to the IoT Hub and continually listens for direct methods, using the MQTT protocol. This is working as expected. I have a second python program that I invoke from cron hourly, that connects to the IoT Hub and updates the device twin for my device. Again this is using MQTT. Everything is working fine.
However I've come across in the documentation that a device can only have one MQTT connection at a time and the second will drop cause the first to drop. I'm not seeing this, however is what I'm doing unsupported?
Should I have a single program doing both tasks and sharing a single connection?
Yes that is correct, you can't have more than one connection with the same device ID to the IoTHub. Eventually in time you will have inconsistency behaviors and that scenario is unsupported. You should use a single program with a unique device ID doing both tasks.
Depending on the scenario you may want to consider using an iothubowner connection string to do service side operations like manage your IoT hub, and optionally send messages, schedule jobs, invoke direct methods, or send desired property updates to your IoT devices or modules.
I am attempting to subscribe to a topic from a node js file.
client.publish('s/us/mqttjs_8303dec3','210,' +Math.random() *10)
I am using this line to publish to a signal strength measurement run on a timer.
All good data arrives in cumulocity
My question is how do I now subscribe to that topic?
How would i do that in mqttlens as a backup?
I am new to cumulocity so any help much appreciated.
Fred
In Cumulocity MQTT is used not as a generic broker where you can publish and subscribe to the same topics.
You currently cannot subscribe on MQTT to the direct data of the devices.
If you (as a device) want to subscribe for your operations you can subscribe to e.g. s/ds for the static operations.
Also for the publish the topic can be simply s/us.
I am not sure what the mqttjs_8303dec3 part is in your case but if it is the client identification you can just put it into the MQTT ClientID to associate with the correct device. No need to send it with every publish.
The MSDN documentation for the BrokeredMessage.Complete method (http://msdn.microsoft.com/en-us/library/microsoft.servicebus.messaging.brokeredmessage.complete.aspx) describes the method as this: "Completes the receive operation of a message and indicates that the message should be marked as processed and deleted or archived."
In my use of this method I've only seen the message deleted once it is processed. This is the one and only instance I've seen in the MSDN documentation, blogs, or anywhere else about Service Bus being capable of archiving old messages.
I could archive the message myself as part of my code that reads and processes a message and then marks it complete. But is it possible to make Windows Server Service Bus archive completed messages for me? If so, how do you turn on and configure this feature?
In case the difference matters, I am using the locally hosted Windows Server Service bus, not the Azure version.
No, Service Bus doesn't archive your messages. I'm going to follow up w/ the documentation folks on what that was supposed to express.