I was trying to trigger an Azure function when a device changes its connection state, so I subscribed the IoT Hub events (Device connected and disconnected) by using Event Grid to trigger my function.
Everything went okay, but I found out that the latency (time between event time and function triggered time) was around 40 seconds to a minute, which wasn't expected.
Is this normal or did I do something wrong? If it's normal, is there any workarounds or other ways to meet my needs? And it will also be great to know why this long latency happens!
Thanks for help!
Does your IotHub and Azure Function are hosted in same region.Assuming that there is no other endpoint (like EventHub) in between.
Related
Looking to understand whether there is a a bulletproof event from the namagedObject side of c8y where we know the device has just connected.
I have a microservice that listens for events in real time and I want to trigger a process once we know a device has connected to send its payload.
We have used:
"c8y_Connection": {"status":"CONNECTED"}
We have had the microservice log to Slack all events from managedObjects where we saw for three days the "status":"CONNECTED" value in the payload of our demo devices at reporting times.
But after three days, we see no more this "CONNECTED" state (all payloads showing "DISCONNECTED").
What I am trying to achieve from the inventoryObject event is to understand when a device had connected and sent payload to know when data had arrived. I then go get the data and process it externally. This is post registration and as part of the daily data send cycle for my type of device.
What would be the best way to understand when a device has sent payload in a microservice? I want to notify an external application with either “data is arriving for id 35213” or even better, “data has arrived for device 35213, and here’s the $payload”.
Just as a general information ahead:
The c8y_Connection fragment showing connected shows an active MQTT connection or an active long polling connection and it is only evaluated once every minute.
So if the client is just sending data and immediately disconnecting afterwards this might not picked up.
If you want to see the device having send something to Cumulocity maybe the c8y_Availability fragment is a better as it holds the timestamp when the device last send something.
{ "lastMessage": "2022-10-11T14:49:50.201+09:00", "status": "UNAVAILABLE"}
Also here the evaluation (or better the update to database) only happens every minute.
Both c8y_Availability and c8y_Connection however are only generated if the availability monitoring has been activated for the device (by defining a required interval for the device).
So if you have activated the availability monitoring and you see a "lastMessage" you can reliably say that the device has already send something to Cumulocity.
I am currently doing a POC where I would like to know if this is possible using Azure Services. I get certain data from Iot hub in my Event hub which triggers a logic app, and based on the message received from Event hub, My logic app would send a message to IoT Edge device. i would like to know if it is possible to send message to IoT hub device from logic app? and if yes how can we do that?
I am more looking Yes or No answer to my question and If I get the services to be used to achieve this.. It will be great
Yes, this is possible. Logic Apps have an Event Hub connector that you can use to start your app when a message comes in.
To send a message to your Azure IoT Edge device from a logic app, you could use the REST API. It allows you to send a direct method to a specific module on the device. The device needs to be online for it to receive the message, otherwise, the REST call will result in an error.
The challenge is that you will need to get a valid security token to complete this call, you could certainly add this to your app as a variable, but you shouldn't. You also run the risk of exposing this secret value in your run history. You could write an Azure Function to generate this security token and retrieve it with the Logic App. At this point you're writing code anyway, the problem you're trying to solve with a Logic App would be a better fit for an Azure Function.
I'm trying to wrap my head around how to subscribe to events in the new Sonos API for an iOS app.
It seems like a cloud service is needed to receive events from the Sonos Cloud.
As described here:
[Subscribing to events with Sonos API
[https://developer.sonos.com/build/direct-control/connect]
Is there any way for an iOS app to subscribe to events (volume and grouping change) without having to run a cloud service?
If not, any features based on event subscriptions will not be able to work if there is trouble connecting to the cloud for whatever reason.
No, there's no way to run without a cloud service. You must have a reliable cloud service for events and subscriptions.
Each device also has a super fast / local / undocumented, UPNP service that also supports events.
this answer should give you some pointers on how to get it working in node.
In a nutshell:
Setup an http endpoint on the device (not sure how that works in Swift)
Tell (in node) the speaker to start sending events for a specific service
Handle the received XML events.
Sample event from RenderingControlService (yes it has nested encoded xml in the <LastChange> property):
<e:propertyset xmlns:e="urn:schemas-upnp-org:event-1-0"><e:property><LastChange><Event xmlns="urn:schemas-upnp-org:metadata-1-0/RCS/"><InstanceID val="0"><Volume channel="Master" val="15"/><Volume channel="LF" val="100"/><Volume channel="RF" val="100"/><Mute channel="Master" val="0"/><Mute channel="LF" val="0"/><Mute channel="RF" val="0"/><Bass val="0"/><Treble val="0"/><Loudness channel="Master" val="1"/><OutputFixed val="0"/><HeadphoneConnected val="0"/><SpeakerSize val="3"/><SubGain val="0"/><SubCrossover val="0"/><SubPolarity val="0"/><SubEnabled val="1"/><SonarEnabled val="1"/><SonarCalibrationAvailable val="1"/><PresetNameList val="FactoryDefaults"/></InstanceID></Event></LastChange></e:property></e:propertyset>
While I am developing the Azure Function App with Event Hub triggered locally, something wired which drew my attention. When I started debugging, my consumer function app will occasionally automatically be triggered with my previous message through event hub, however, I didn't even fire my event hub publisher at that time! It felt like some event messages were stored in some cache places where I have no idea where they are, that were also trying to trigger my function app from background again and again...
My App settings for my function is using UseDevelopmentStorage=true, and is not related to any of my storage account, in addition above scenario did not always happen every time, but it made me concerned because I had no idea why the same message to be triggered multiply times that are out of my control, once message were published and consumed by function app, it should disappear from event hub message queue, right?
Can anyone please let me know where I can check my messaged stored locally or when published in Azure portal? Thank you very much!
Can anyone please let me know where I can check my messaged stored
locally or when published in Azure portal?
Firstly,i'm afraid that azure function won't save your messages into cache.Based on the official document:
When all function execution completes (with or without errors),
checkpoints are added to the associated storage account. When
check-pointing succeeds, all 1,000 messages are never retrieved again.
Above is description of event hub checkpoint mechanism.Besides,you could refer to this blog. The AzureWebJobsStorage is set to be UseDevelopmentStorage=true when you debug function locally,so i suggest you checking the data in the local storage account.When you run it on the portal,associated storage account will be checked.
Here are some similar issues for your reference:
1.https://github.com/Azure/azure-functions-host/issues/2796
2.https://github.com/Azure/Azure-Functions/issues/589
3.https://github.com/Azure/azure-event-hubs-dotnet/issues/358
Of course,you could open a stack here to get more help.
Hello I am trying to create a simple push-notification system similar to this common use case:
1. The user gets a chest and can either watch an ad to skip the wait time or wait one hours for the chest to open. The app sends an upstream request which sets up a downstream push notification that shall be delivered in one hour to let the user know the chest is ready.
2a. The user then waits an hour, gets a push notification (outside of the app) to open their chest and they do!
or
2b. They wait 20 minutes then decide to watch the ad. The app sends an upstream request which cancels the pending push notification which would have otherwise been delivered in 40 minutes.
Okay awesome so that is the problem and I am having a hard time understanding how to do this. I have looked over the documentation for each of these programs but they seem designed for downstream push notifications. It just seems odd there is no built-in support for this use case. It seems like such a common use case.
I so far found 3 solutions that will integrate into my cross-platform Unity setup and provide services for free or super-cheap:
Amazon Simple Notification Service (SNS)
Google Firebase Cloud Messaging (FCM)
OneSignal
Amazon seems to group clients into "Topics" so I guess I would be setting up a one-device-topic and essentially. I can subscribe and unsubscribe from them but it doesn't seem to support a topic with a 60 minute delay.
2a. Create a topic: https://docs.aws.amazon.com/sns/latest/dg/sns-tutorial-create-topic.html (it would just include the current device)
2b. Subscribe to it
2c. Send a message to it https://docs.aws.amazon.com/sns/latest/dg/sns-tutorial-publish-message-with-attributes.html
So basically I can add attributes to my message but it would seem I need to implement the server-side code to read a delay attribute then somehow queue a message for delay. Maybe I am missing something?
For Firebase I pretty much see the same thing as Amazon. There are topics https://firebase.google.com/docs/cloud-messaging/android/topic-messaging and a means to send upstream messages https://firebase.google.com/docs/cloud-messaging/android/send-with-console but with the messages I don't see anyway here to get the time delay https://firebase.google.com/docs/cloud-messaging/unity/topic-messaging I see conditions towards the bottom of that article but I don't know if it is meant for this use case.
OneSignal has the easiest to scroll-through API. I'll refer to some strings that you can CTRL-F by using the format ("Create Notif") because everything is on this one page: https://documentation.onesignal.com/reference
So basically I can ("Send to Specific Devices") which I guess would be the sending device, then I can ("Schedule notification for future delivery.") using the send_after parameter. And finally, if need be, I can ("Cancel notification"). So this appears to be everything I need. I'm currently looking at this option and trying to figure out how to actually get this working.
So there is my progress over the last few hours researching each of these options. I am hoping you can help me better understand how I may be misunderstanding the above options as this seems to me a very common use-case. Perhaps I am just not googling the question correctly. Any help appreciated.
Whenever there's a likelihood that you'll need to cancel a significant percent of the notifications you send, you should use local notifications. That way you can easily schedule and cancel them locally without making any network requests. Also, this solution works for offline devices which is great for games (played on planes, etc...)