Timer stops unexpectedly - azure

I was following the chnage notification example in
https://github.com/microsoftgraph/msgraph-training-changenotifications.
I had succesfully replicated it and deployed it to Azure.
But the timer function in the Get method of the Notification Controller stops getting triggered sometimes. Sometimes it happens just like that and sometimes after a fresh deployment of code to Azure.
Is there any work around or any alternative for the Timer class which is good for production app?

Related

Handle timeouts of Node Function Apps

I created an Azure Function App with a Node runtime, which works properly on local and manually created cloud environments.
But when it becomes deployed via Azure Pipelines, it writes a message via context.log and seems working but finally it raises Timeout error.
Timeout value of 00:05:00 exceeded by function 'Functions.<...>' (Id: '<...>'). Initiating cancellation.
I guess, that there is some blocking Node expression because of misconfiguration, but there is no further context logged by Application Insights.
There is a way to handle the cancelation event within your Function App to provide some Node runtime information (e.g. via SIGINT callbacks)?
I've tried to reproduce this issue but failed. But I got some similar question here and noticed we can set functionTimeout value in host.json file. How about trying it.

Azure Function - Event Hub Trigger stopped

I've got an Azure Function app in production on an event hub trigger, it's low throughput with the function typically only being triggered once daily. It's running on an S1 plan at the moment and has a few other functions such as timer triggered and HTTP triggered.
It's been running fine but today it stopped being triggered by new messages until I restarted the app. All other functions were working just fine and responding to their associated triggers.
I've look through App Insights and there are no reported errors or issues, it's just not doing anything.
Has anyone else had this issue or know of what may be causing it?
First of all - is your App Service has Always On enabled?
Second thing - have you tried to test your trigger locally, so you can be sure, that there are no issues with your Event Hub?
Personally, I faced such issues when Event Host Processor implemented in EventHubTrigger was losing a lease because of additional processor introduced. It is also possible, that since it faces a low throughput, it lost a lease and for some reason was not able to renew it:
As an instance of EventProcessorHost starts it will acquire as many
leases as possible and begin reading events. As the leases draw near
expiration EventProcessorHost will attempt to renew them by placing a
reservation. If the lease is available for renewal the processor
continues reading, but if it is not the reader is closed and
CloseAsync is called - this is a good time to perform any final
cleanup for that partition.
https://blogs.msdn.microsoft.com/servicebus/2015/01/21/event-processor-host-best-practices-part-2/
Nonetheless, it is worth to contact the support to make sure there were no other issues.

Azure Functions: Application freezes - without any error message

I have an Azure Functions application which once in a while "freezes" and stops processing messages and timed events.
When this happens I do not see anything in the logs (AppInsight), neither exceptions nor any kind of unfamiliar traces.
The application has following functions:
One processing messages from a Service Bus topic subscription (belonging to another application)
One processing from an internal storage queue
One timer based function triggered every half hour
Four HTTP endpoints
Our production app runs fine. This is due to an internal dashboard (on big screen in the office), which polls one of the HTTP endpoints every 5 minutes, there by keeping it alive.
Our test, stage and preproduction apps stop after a while, stopping to process messages and timer events.
This question is more or less the same as my previous question, but the without error message that was in focus then. Much fewer error messages now, as our deployment has been fixed.
A more detailed analysis can be found in the GitHub issue.
On a consumption plan, all triggers are registered in the host, so that these can be handled, leading to my functions being called at the right time. This part of the host also handles scalability.
I had two bugs:
Wrong deployment. Do zip based deployment as described in the Docs.
Malformed host.json. Comments in JSON are not right, although it does work in most circumstances in Azure Functions. But not all.
The sites now works as expected, both concerning availability and scalability.
Thanks to the people in the Azure Functions team (Ling Toh, Fabio Cavalcante, David Ebbo) for helping me out with this.

Azure Function app periodically not firing on trigger or timer

I have an Azure Function app with 4 functions
one triggered on a timer every 24 hours
one triggered on events from IoT Hub
two others triggered on events from Service Bus as a result of the previous function
All functions work as expected when first deployed but after a period of time the functions stop running and the app appears to be scaled down with no servers online. At this point the functions are never triggered again unless I either restart the app, or drill into a function and view details of it (supposedly, forcing the function to start up).
I have the exact same code deployed to a different environment and it runs perfectly and has never encountered this issue. I've checked all the settings and configuration and can't see any material differences between the two.
This is really frustrating and is becoming a big issue. Any help would be much appreciated.
Function App is hosted in Australia Southeast.
This is the last execution (as of now)
10:45 PM UTC - Function started (Id=4d29555b-d3af-43d7-95e9-1a4a2d43dc46)
The event triggered function should run every few minutes as the IoT Hub it's triggering from has a steady stream of events coming in. When I prod the function (or restart it) and it comes to life it quickly churns through a backlog of messages queued in the IoT Hub.
I see the problem: you have comments in your host.json, which makes it invalid and throws off the parser at the scale controller level.
Admittedly, the error handling is quite poor here. But anyway, remove the commented out logger, and it should all work.

Google App Engine - nodejs application goes down over night

Hi I am using google app engine to host a single instance nodejs application. The application works fine and my scripts are showing no errors in the logs. The application is currently just in testing and is not getting used over night, however often I come to work the next day and the server is just returning internal server errors. No errors are shown in my application log other then the 502 errors which i get when trying to access the next day. I see like 100s of calls for /_ah/_background/ overnight some appear to have timed out. At this point I must restart my instance for the app to continue to function.
I am completely stumped.. Because my app using web-sockets I must use manual scaling and a single instance. Would appreciate any help / suggestions.
I would venture a gues that you have a deferred task stuck running. Tasks that run in the taskqueue api are set by default to continuously retry. You can visit the taskqueue api TaskQueue API
To get the tasks to stop running right now visit the Google Cloud Console
select your project. Then select App Engine. Then select Task queues. Click on the task that is running (probably default). There should be a option to Pause the queue. This should prevent the 500 errors from occurring but will not fix the reason the task is failing.

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