Disabled Azure Functions still running - azure

I am just starting to test with Microsoft Azure Functions. I have my VS2017 publishing and my function is working nicely. I currently have one function that I am working with. It is set on a timer of every 5 minutes.
However, it appears that that function is executing even when I have it "disabled". This can be seen in the Monitor and in one of the systems that it is interacting with. The only way that I am able to stop it is to stop the overall function group. When I then start the function group, it starts the disabled function running every 5 minutes again.
Am I missing something? Does the disabling of an individual function have some other purpose?
How do I get an individual function within a function group to not execute on its defined schedule?
Thanks.

What you are experiencing is an expected behavior though not an ideal one. It is a bug in the portal experience.
The Function runtime directly consumes metadata in the binary files of the pre-compiled functions. Here is sample of annotation for the disabled function.
[TimerTrigger("0 */5 * * * *"), Disable()]
This is the function.json generated by visual studio the above annotations.
{
"generatedBy": "Microsoft.NET.Sdk.Functions.MSBuild-1.0.2",
"configurationSource": "attributes",
"bindings": [
{
"type": "timerTrigger",
"schedule": "0 */5 * * * *",
"useMonitor": true,
"runOnStartup": false,
"name": "myTimer"
}
],
"disabled": true,
"scriptFile": "..\\bin\\FunctionApp3.dll",
"entryPoint": "FunctionApp3.Function1.Run"
}
The function.json generated by the precompiled functions is consumed by the portal and that is what is shown in the portal. When you change the disabled state of the function in the portal the disabled property is changed in the function.json but it is not consumed by the functions runtime. Hence it continues to execute.
When you deploy it in disabled state, runtime is aware of it and honors it as expected.
I have opened this bug to fix the portal experience.
https://github.com/Azure/azure-functions-ux/issues/1857

Today, I got the same problem, and after to disable the function in Azure, I recommend you to restart the Function service. Because the Azure needs to refresh the metadata, and the restart is one of the solutions to accomplish it.

Related

Azure function takes a really long time to trigger

We have an Azure function v3 running Node, consumption plan, with an input trigger connected to a cosmos database. The function.json looks like this:
{
"disabled": false,
"bindings": [
{
"type": "cosmosDBTrigger",
"name": "productDocuments",
"collectionName": "products",
"direction": "in",
"connectionStringSetting": "DB_CONNECTION_STRING",
"databaseName": "product-management",
"createLeaseCollectionIfNotExists": true,
"maxItemsPerInvocation": 1
},
{
"name": "productDocument",
"type": "cosmosDB",
"databaseName": "product-management",
"collectionName": "products",
"createIfNotExists": true,
"connectionStringSetting": "_DB_CONNECTION_STRING",
"direction": "out"
}
],
"scriptFile": "dist/nameOfFunction.js"
}
But this trigger is working really, really slow and unreliable. If we add an item to the DB it sometimes triggers straight away, sometimes it seems to take hours and sometimes not at all. I am manually monitoring the cosmos db so I can see that items are added.
I am looking at this page, and most of the time nothing happens. I don't know how else to debug this
Should it really take hours for an invocation to show up here? Or is it the trigger that's unreliable?
General guidance is in this doc: https://learn.microsoft.com/azure/cosmos-db/troubleshoot-changefeed-functions#my-changes-take-too-long-to-be-received
What happens on Consumption Plan is that, after a period of inactivity, instances are deprovisioned. When a new instance is provisioned, it hits a cold start.
The key part here is that, when your instances are deprovisioned, they are not checking the Change Feed for events, so how does Functions know when to "wake them up"?
There is a periodic check done by an external component that checks to see if there are new changes, if there are new, then it would provision new instances of your Function to start consuming them.
This external component in your case, could be having an issue or delays in this checks.
If you have no Function logs for an hour even though you are making changes to the monitored collection, I would try to contact Azure Support to understand why is your Function not "waking up".
One of the known issues I've heard about was related to where the Cosmos DB Connection Strings were stored. Apparently this component at some point (maybe it's already fixed) had a problem where it could not access the Connection String if it was saved in "Connection Strings" section of the Function configuration, but was looking for it only on the "App Settings". In this cases, it could not wake up the Function and the Function only woke up if someone opened it on the Azure Portal. My recommendation would be to check where are you storing your connection string and see if you can move it to "App Settings" and see how it behaves.
Our problem with this was that we had two separate functions that both had a CosmosDBTrigger on the same collectionm but used the same lease, and apparently you can't do that. So it was solved by setting two separate leases (we used the leaseCollectionPrefix in the function.json.)

Whats is the difference between 'Settings.job' and 'TimerTrigger' in Azure WebJobs SDK 3.0

There are many tutorials using the following code to create a Webjobs via the WebJob SDK 3.0 library. Specifically 'TimerTrigger'
public void DoSomethingUseful([TimerTrigger("0 */1 * * * *", RunOnStartup = false)] TimerInfo timerInfo, TextWriter log)
{
// Act on the DI-ed class:
string thing = _usefulRepository.GetFoo();
Console.WriteLine($"{DateTime.Now} - {thing}");
}
The above example should run this method as a webjob every 1 minute. However this doesn't work.
I have managed to get the webjob to work when including a setting.job file.
setting.job: { "schedule": "0 */1 * * * *" }
My question is what is the different between these two?
Update:
Please go to the azure webjobs log, then you can see it actually runs as per the timerTrigger defined by SDK(even though the Schedule is n/a, and settings.job is blank, it does not matter):
In short, When using webjob sdk 3.x, you can use TimerTrigger attribute to run the function as per the time you defined. Without using webjobs SDK(like use .zip file or publish a console project from visual studio), you can use setting.job to defined timer instead of TimerTrigger attribute.
1.When you're using webjobs SDK 3.x for timer trigger, you should add this line of code: config.AddTimers(); .
Here are my code using webjobs SDK 3.x(it's a .net core 2.2 console project created in visual studio):
The packages with latest version: Microsoft.Azure.WebJobs / Microsoft.Azure.WebJobs.Extensions / Microsoft.Extensions.Logging.Console
The code in Program.cs:
class Program
{
static void Main(string[] args)
{
var builder = new HostBuilder()
.ConfigureWebJobs(config =>
{
config.AddTimers();
config.AddAzureStorageCoreServices();
})
.ConfigureLogging((context, b) =>
{
b.AddConsole();
}
)
.Build();
builder.Run();
}
}
Then create a new file, like SayHelloWebJob.cs, and code in it:
public class SayHelloWebJob
{
public void ProcessCollateFiles([TimerTrigger("0 */1 * * * *", RunOnStartup = false)]TimerInfo timerInfo,TextWriter writer)
{
writer.WriteLine("hi, it is a testing running");
Console.WriteLine("test");
}
}
Note that in the appsettings.json file, add your storage connection string, like below:
{
"AzureWebJobsStorage": "DefaultEndpointsProtocol=https;AccountName=xxx;AccountKey=xxx;EndpointSuffix=core.windows.net"
}
Then run the project, you can see the function is triggered as per 1 minute:
2.For settings.job, eg. if you're just creating a console project, and does not use the webjobs sdk. Since you're not using webjobs sdk, you cannot use the timerTrigger attribute. At this moment, you can include the settings.job file(in it's property, set "Copy to Output Directory" as "copy if newer") in this project and configure the scheduled timer like you did in your post. After publish as webjob(from visual studio, when publish, select "Webjob run mode" as "run on demand"), it can run as per the schedule you defined in settings.job.
I have been struggling with the same problem. Here is my understanding after longer research.
There are two kind of Webjobs:
triggered
continuous
Triggered one has to be triggered manually or can be triggered by App Service as per CRON expression schedule provided in setting.job. These jobs are not present in memory once not running.
Continuous one runs always, so the process exists in memory all the time. You can schedule it using Webjobs SKD TimeTrigger attribute.
You will also notice difference between these two Webjob types in the Dashboard.
For triggered Webjobs you will see on top level jobs runs then functions invoked and eventually invocation details.
For continuous Webjobs this will be functions invoked and eventually invocation details. Job runs are missing as this is just one long running job.
Check App Service / Process explorer under Kudu w3wp process to see Webjobs processes running.
Note that continuous and triggered Webjobs have to be started in different way in Main method where you provide the configuration. All comes configured when Webjob of specific type is added via Visual Studio.
This is based on WebJobs 2.x.
My recommendation is
for periodical (e.g. once per few hours, days) jobs use triggered
ones, job when not running will not consume resources,
for more frequent jobs use continuous ones with TimeTrigger
attribute, it will consume resources all the time but will not need
extra time for start-up.

How to set up a multi-user environment for Azure Functions using queues?

We have started to use the Queue binding in our Azure functions for longer-running tasks such as sending bulk e-mails and "clean-up" tasks for CosmosDB. We develop locally with the Functions emulator then commit into VSTS/Azure DevOps which then auto-deploys into our Function App.
It seems as though pretty quickly we're going to have multiple Functions (two local emulators and one cloud function) all listening to the same queue. We tried disabling locally and renaming locally, but these all seem like awkward workarounds that require too much manual work and have the possibility to push the wrong queue name forward into VSTS.
How do we configure the queue name in the function.json to read an environment variable? The connection setting in the binding takes the name of an environment variable, but the queue setting wants a string.
{
"disabled": false,
"bindings": [
{
"name": "myQueueItem",
"type": "queueTrigger",
"direction": "in",
"queueName": "emailer",
"connection": "STORAGE_CONNECTION_STRING"
}
]
}
Just wrap variable name with % and function can read its value from Application settings on portal and Values in local.settings.json locally.
"queueName": "%myqueue%"
connection property of triggers and bindings is a special case and automatically resolves values as app settings, without percent signs.
See Binding expressions - app settings.

Azure function is not triggering on scheduled time

Note: Even though it may seem duplicate, My issue is different and I request you to read complete description before hastily marking the question down just by reading Question title.
I opened "Azure function is not triggering on scheduled time " issue on official "azure-webjobs-sdk-script" git repository on May 24, 2017-but there is no reply yet. So I am re-asking this here.
I am using azure function in consumption plan, and have scheduled it to execute at every 4.00 am utc by setting following cron expression in function.json:
{
"bindings": [
{
"name": "myTimer",
"type": "timerTrigger",
"direction": "in",
"schedule": "0 0 4 * * *"
}
],
"disabled": false
}
Azure function does get execute on time only if I am logged into portal or clicks on function blade. It does not invoke when I am logged out from portal (suggesting either system listener or function go to sleep after some interval).
Their official documentation states that functions in consumption plan do not require any other settings (like Always on) to keep the function alive, instances of the Azure Functions host are dynamically added and removed based on the number of incoming events.. So as per documentation, no other settings I have to configure to execute function in consumption plan.
What I have tried?
From "Timer triggered azure function not getting triggered" question on SO, I re-checked and ensured my plan (consumption plan) and time zone. (I want it to run in utc, so no explicit setting is required)
From "#1445: Azure function timer trigger not firing" git issue, I checked whether it was just logs that are not appearing. But I am certainly sure, that its not the logs but the actual function does not get triggered unless I am having my portal on or trigger it manually.
I tried to check whether this behavior exists if I change the schedule to a more closer recursive invocations--I scheduled function to get executed at every 2 hours, and this schedule perfectly worked even when I logged out or did not awake function manually. This means, there is some issue when schedule is set to run on larger set of intervals (in my case each day)
As discussed here in #1534, deleting and redeploying the function completely in new function app did not reproduce the issue. So deleting the function and/or function app-and redeploying the same should make things working. Meanwhile, Azure team has announced to add internal logging which will help future diagnosis.

Azure Function Multiple Job Hosts

I am experiencing a strange problem with Azure Functions that is starting up multiple job hosts. The initial host seems to startup and subsequent hosts error trying to acquire singleton lock. It is really noticeable when I disable one of the jobs and the error message appears that the "function runtime is unable to start". I noticed that my timer triggers were executing multiple times per their configuration "0 */30 * * * *" which caused me to dig deeper into this situation.
Pid 1 2017-04-25T13:30:06.680 Staging table updated successfully.
Pid 1 2017-04-25T13:30:06.680 Updating the base table from the staging table.
Pid 2 2017-04-25T13:30:06.680 Staging table updated successfully.
Pid 2 2017-04-25T13:30:06.680 Updating the base table from the staging table.
Details about the Function App:
- Azure Function running under the Dynamic/Consumption plan
- 5 functions running from class libraries (followed this guide - https://blogs.msdn.microsoft.com/appserviceteam/2017/03/16/publishing-a-net-class-library-as-a-function-app/)
- 2 functions are executed from a timer, every 30 minutes "0 */30 * * * *"
- 1 timer trigger disabled while waiting for development time
- 1 blob trigger watching a container for uploads from IoT Hub
- 1 EventHub trigger receiving events from IoT Hub (sparse events so no heavy load here)
Steps to reproduce:
- Stand up Azure function with Dynamic plan
- Create the Azure functions in the portal (ran into issues not doing this prior)
- Deploy the functions from VSTS, using WebDeploy from the guide above
- Make sure the functions tried to start
- Disable one of the functions to force a restart
- Error messages start displaying
Log pulled from the Function:
Link to log file
I have stopped the Azure Function App Service, removed the lock folder to see if that helps acquire singleton locks which it does, but as soon as a function is enabled/disabled or pushed from VSTS using the web deploy the errors return. I have rebuilt the Azure Function a couple of times and the outcome is still the same.
We are in the process of trying to understand how to troubleshoot this issue so we can create a monitoring process around this scenario.
Edit
The function that executed twice is setup with the following (all of the functions look very similar to this):
function.json
{
"scriptFile": "..\\bin\\IngestionFunctionClassLibrary.dll",
"entryPoint": "IngestionFunctionClassLibrary.Functions.AnalyticsUpdate.Run",
"bindings": [
{
"name": "myTimer",
"type": "timerTrigger",
"direction": "in",
"schedule": "0 */30 * * * *"
}
],
"disabled": true`
}
project.json
{
"frameworks": {
"net46":{
"dependencies": {
}
}
}
}
Messages that look like Unable to acquire Singleton lock are actually not errors, but simply informational messages. What it means that your Function App was scaled out to multiple instances (in your case about 5). There are some lease resources that can intrinsically only be held by one instance (to support singleton behavior). So once an instance gets the lease, all others will display this message.

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