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.
Related
I have 2 simple questions that I did not find by reading the official documentation about google nearby message API
https://developers.google.com/nearby/messages/android/pub-sub
If you publish multiple messages with the publish method (on the same instance of an app), the messages are saved as several different messages or are updated and overwritten (on cloud console)?.
Is it possible with the publish method to update a message?
I'm building an application where each user sees what others are posting, but I just need to know the most up-to-date data of each user, I don't need all the messages.
Thank you.
With PubSub, you publish message in a queue. Then you can't update or delete them, they are published.
On the consumer side, the messages are usually distributed in the order, but without any guarantee. In each message, you have a published timestamp.
In your use case, it could be interesting to keep in memory the userID and the latest processed timestamp. If you application is distributed, the best is to store these data in memorystore.
Like that, when a message comes in
Either it is newer than the value in memory store and your process it
Or, it's older and your trash it.
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...)
In Android, an app which is not currently running can be notified when certain event happens (like wifi scan results available, boot process completed) through Broadcast Receivers mechanism. Is this possible in anyway so that the wifi/geo triggers can be invoked even if the Worklight app is not running, including not running in the background?
Regarding wifi/connectivity changes notifying your app, that looks possible since it is a standard system event. It would likely take custom native code since you'd need to implement a broadcast receiver. And you'd need to register your receiver in your app's AndroidManifest.xml file. Take a look at http://developer.android.com/reference/android/net/ConnectivityManager.html and http://www.grokkingandroid.com/android-getting-notified-of-connectivity-changes/
Regarding geolocation triggers, it is unclear what sort of triggers you are looking for. This is all I see in the Android docs: http://developer.android.com/reference/android/location/GpsStatus.html and the standard broadcast actions at http://developer.android.com/reference/android/content/Intent.html#constants
If you are looking for something like geofencing, it would take application logic to determine when to fire events, so that means an app or service needs to be running. So although your broadcast receiver's onReceive() method can get called upon a geo event, who is going to fire that event?
Having the triggers activate when the application is not running at all (not even in background) isn't supported through the Worklight APIs.
You could try and use Worklight Android Native SDK together with cmarcelk's suggestions. Or you could use the Worklight Android triggers within a native service, together with the Broadcast Receivers mechanism so that it will run automatically on boot. You could then use an Intent to open the application from the trigger callback.
I've got a JMS messaging system implemented with two queues. One is used as a standard queue second is an error queue.
This system was implemented to handle database concurrency in my application. Basically, there are users and users have assets. One user can interact with another user and as a result of this interaction their assets can change. One user can interact with single user at once, so they cannot start another interaction before the first one finishes. However, one user can be in interaction with other users multiple times [as long as they started the interaction].
What I did was: crated an "interaction registry" in redis, where I store the ID of users who begin an interaction. During interaction I gather all changes that should be made to the second user's assets, and after interaction is finished I send those changes to the queue [user who has started the interaction is saved within the original transaction]. After the interaction is finished I clear the ID from registry in redis.
Listener of my queue will receive a message with information about changes to the user that need to be done. Listener will get all objects which require a change from the database and update it. Listener will check before each update if there is an interaction started by the user being updated. If there is - listener will rollback the transaction and put the message back on the queue. However, if there's something else wrong, message will be put on to the error queue and will be retried several times before it is logged and marked as failed. Phew.
Now I'm at the point where I need to create a proper integration test, so that I make sure no future changes will screw this up.
Positive testing is easy, unfortunately I have to test scenarios, where during updates there's an OptimisticLockFailureException, my own UserInteractingException & some other exceptions [catch (Exception e) that is].
I can simulate my UserInteractingException by creating a payload with hundreds of objects to be updated by the listener and changing one of it in the test. Same thing with OptimisticLockFailureException. But I have no idea how to simulate something else [I can't even think of what could it be].
Also, this testing scenario based on a fluke [well, chance that presented scenario will not trigger an error is very low] is not something I like. I would like to have something more concrete.
Is there any other, good, way to test this scenarios?
Thanks
I did as I described in the original question and it seems to work fine.
Any delays I can test with camel.
I have submission web page, after submission i am sending the data to workflow to save it to the database this also stores the instance created by the workflow in workflow database. my expection is to have instance in DB as IDLE. and whenever i required i can reload the instance. but currently it creates record in instance table of workflow database with executionstatus = closed and iscompleted = 1. Please let me know how to set it to IDLE(or relevant status)
You can't change the status back to idle. Your workflow started and finished and that is it. If you want your workflow to remain alive you have to make sure it do so in the workflow by adding bookmarked activities like the Receive or Delay activity. But without more info on the workflow determining what is going wrong is real hard.