I'm experiencing TimerTrigger not actually triggering in multiple of my Azure Functions. The flow always looks similar to this:
As shown in the log statements, this timer is configured to trigger every 5 minutes (0 */5 * * * *). It triggers 5:10, 5:15, ... 5:40. But then on 5:45 no trigger. The same goes for 5:50. Then at 5:51 it "wakes up". I have RunOnStartup = true on my trigger, so this is probably caused by the function app being started.
My function app is consumption based, why I would expect the app to simply run on another machine if the current machine is shot down or in other ways unavailable. The app is running on Azure Functions version 3.
Am I missing something here, or does anyone experience similar issues?
AFAIK, There is no specific reason for the timer trigger not firing properly within the given time.
Few of the workaround we can follow,
I have not faced the similar issue yet, would suggest you to please try to restart/refresh your function app.
or, It may be due to of the sync issue with the function which is not happening properly.
As suggested by #Anand Sowmithiran the SO THREAD, #MayankBargali-MSFT suggest about singleton lock i,e;
TimerTrigger uses the Singleton feature of the WebJobs SDK to ensure
that only a single instance of your triggered function is running at
any given time. When the JobHost starts up, for each of your
TimerTrigger functions a blob lease (the Singleton Lock) is taken.
This distributed lock ensures that only a single instance of your
scheduled function is running at any time. If the blob for that
function is not currently leased, the function will acquire the lease
and start running on schedule immediately. If the blob lease cannot be
acquired, it generally means that another instance of that function is
running, so the function is not started in the current host.
Also please try to set runonstartup to false to check whether its behaving the same or not as provided the MS DOC in comment.
For more information Please refer the below links :-
MS Q&A| Azure Timer Trigger not firing
GitHub | azure timer function not executing all of sudden
Related
Because http-trigger azure function has a strict time limit for 230s, I created a http-trigger durable azure function. I find that when I trigger durable function multiple times and if the last run is not completed, the current run will continue the last run until it is finished. It is a little confused for me because I only want each run to do the task of the current run, not replay the last un-finished run. So my question is that:
Is it by design for durable function to make sure each run is completed (succeed or failed)?
Can durable function only focus on the current run just like the normal http-trigger azure function?
If 2) is not, is there any way to mitigate the time limit issue for normal http-trigger azure function?
Thanks a lot!
The function runs until it gets results that is Successfully completed or failed message.
According to Microsoft-Documentation it says,
Azure Functions times out after 230 seconds regardless of the functionTimeout setting you've configured in the settings.
I have a timer trigger Function App ("version": "2.0") in azure which runs every 5 min. Cron Expression Used- 0 */5 * * * *
Its working as expected but sometimes it suddenly stops running. If I disable the function app and re-enable it, its starts working again.
If you see the screenshot below, It stopped working from 2021-04-14 16:54:59.998 to 2021-04-14 20:55:12.139
Any Help will be appreciated.
There could be different reasons for this issue and I will suggest you to review the below document to troubleshoot the issue and see if you are able to find the root cause.
Timer triggered function app uses TimerTriggerAttribute. This attribute consists of the Singleton Lock feature which ensures that only a single instance of the function is running at any given time. If any process runs longer than the scheduled timer, the new incoming process waits for the older process to finish and then uses the same instance. If you are using the same storage account across different timer trigger functions then this could be one of the reasons as mentioned here.
The other reason could be a restart and I will suggest you to check the Web App Restart detection section.
https://github.com/Azure/azure-functions-host/wiki/Investigating-and-reporting-issues-with-timer-triggered-functions-not-firing
https://github.com/Azure/azure-webjobs-sdk-extensions/wiki/TimerTrigger#troubleshooting
I need to develop a process (e.g. Azure fucntion app) that will load a file from FTP once every week, and perform ETL and update to other service for a long time (100mins).
My question is that will Timer Trigger Azure Function app with COMSUMPTION plan works in this scenario, given that the max running time of Azure function app is 10 mins.
Update
My theory of using Timer trigger function with Comumption plan is that if the timer is set to wake up every 4 mins from certain period (e.g. 5am - 10am Monday only), and within the function, a status tells whether or not an existing processing is in progress. If it is, the process continues its on-going job, otherwise, the function exits.
Is it doable or any flaw?
I'm not sure what is your exact scenario, but I would consider one of the following options:
Option 1
Use durable functions. (Here is a C# example)
It will allow you to start your process and while you wait for different tasks to complete, your function won't actually be running.
Option2
In case durable functions doesn't suit your needs, you can try to use a combination of a timer triggered function and ACI with your logic.
In a nutshell, your flow should looks something like this:
Timer function is triggered
Call an API to create the ACI
End of timer function.
The service in the ACI starts his job
After the service is done, it calls an API to remove it's own ACI.
But in anyway, durable functions usually do the trick.
Let me know if something is unclear.
Good luck. :)
With Consumptions plan, the azure function can run for max 10 minutes, still, you need to configure in host.json
You can go for the App Service Plan which has no time limit. Again you need to configure function timeout property in host.json
for more seed the following tutorial
https://sps-cloud-architect.blogspot.com/2019/12/azure-data-load-etl-process-using-azure.html
I am wondering if a Semaphore (lock) would work in Azure functions.
I do not want two separate webjobs running at the same time. The webjobs live on the same app service plan.
Is this something I can guarantee with a semaphore? (as this enables cross process locking?)
First question: you're talking about Functions and WebJobs. Which one is it?
If your App Service Plan does any scaling, the semaphore will not work since two instances might be started on two different machines. The good thing: (for WebJobs) there's a simple solution for that.
[Singleton]
public static async Task ProcessImage([BlobTrigger("images")] Stream image)
{
// Process the image
}
In this example, only a single instance of the ProcessImage function will run at any given time. When the function is triggered by a new image being added to the images container, the runtime will first attempt to acquire the lock (blob lease). Once acquired, the lock is held (and the blob lease is renewed) for the duration of the function execution, ensuring no other instances will run. If another function instance is triggered while this function is running it will wait for the lock, periodically polling for it.
You can find more information here: Azure WebJobs SDK - Singleton
Edit:
If you're using Azure Functions: those running based on a TimerTrigger seem to run as Singletons.
The timer trigger supports multi-instance scale-out. A single instance of a particular timer function is run across all instances.
I have a time-triggered azure function triggered every 1 hour. My requirement is that, it should get triggered every hour but once also immediately after the deployment ?
Is playing with cron expression my only way for this ?
There isn't something directly tied to the deployment. The runOnStartup setting, documented here, triggers your function when the runtime starts, but won't cause the runtime to start as a result of a deployment.
Your best option would likely be to customize your deployment, as documented here, and invoke your function (by issuing an HTTP request) once the deployment completes. You can share the code and have an HTTP triggered function that uses the same logic as the timer function that runs on a schedule.