Scheduled WebJob - azure

I'm creating a new Azure WebJob project -- which appears to be a polished version of a console app that can run as a web job.
I want this job to run based on a schedule but in the Main() method -- see below -- Microsoft gives you the host.RunAndBlock() for the job to run continuously.
Do I need to change that if I want the job to run at regularly scheduled intervals?
static void Main()
{
var host = new JobHost();
// The following code ensures that the WebJob will be running continuously
host.RunAndBlock();
}

When using the Azure WebJobs SDK you can use TimerTrigger to declare job functions that run on a schedule. For example here's a function that runs immediately on startup, then every two hours thereafter:
public static void StartupJob(
[TimerTrigger("0 0 */2 * * *", RunOnStartup = true)] TimerInfo timerInfo)
{
Console.WriteLine("Timer job fired!");
}
You can get TimerTrigger and other extensions by installing the Microsoft.Azure.WebJobs.Extensions nuget package. More information on TimerTrigger and the other extensions in that package and how to use them can be found in the azure-webjobs-sdk-extensions repo. When using the TimerTrigger, be sure to add a call to config.UseTimers() to your startup code to register the extension.
When using the Azure WebJobs SDK, you deploy your code to a Continuous WebJob, with AlwaysOn enabled. You can then add however many scheduled functions you desire in that WebJob.

An easy way to trigger a WebJob on a schedule would be to code it as a regular console application, and just add a 'settings.job' with the cron based scheduling configuration to the project.
For example, the following definition would trigger it every 5 minutes:
{
"schedule": "0 */5 * * * *"
}
No need to use JobHost, just make sure your WebApp is configured as 'Always On'.
You should then deploy the job as a triggered WebJob.

There are 2 ways that I know of for scheduling a web job instead of making it run continiously:
Create a scheduled WebJob using a CRON expression
Create a scheduled WebJob using the Azure Scheduler
You can find the documentation for both ways on azure.microsoft.com
I think you need RunAndBlock in case of Scheduled or Continuous but you can remove it if you have your job as on-demand

Related

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.

Azure WebJob has status "Never finished" in WebJobs Dashboard

I have long running web job in AppService (around 1h).
AppService has "Always on" turned on.
It is initialized with:
var host = new JobHost(config);
host.Call(typeof(Functions).GetMethod("SyncUsers"));
host.Start();
Actual methods SyncUsers wrapped with attributes:
[Timeout("00:59:00", ThrowOnTimeout = true)]
[NoAutomaticTrigger]
Schedule is set with settings file settings.job:
{
"is_singleton": true,
"schedule": "0 0 */4 * * *"
}
Main issue is that in WebJobs Dashboard I see status "Never finished" in 90% of cases (or failed with exception - OK situation). Running time for such jobs is different: from 5 min to 30 mins. Logs just stopped at some moment without any exception or detailed message.
Another thing is that I can see that multiple jobs are running in the same time. So looks like singleton and schedule don't work (since job should run every 4h).
Also some jobs that have this status, displayed without running time, like this: "1 hour ago ( running time)" and I am not able to see logs or download them.
Anybody had such experience?
Thank you
Looks like you're trying to run an executable that never ends as a triggered WebJob, which has no chance of working. You need to either:
Use a continuous WebJob and rely on the WebJobs SDK for your timer
Use a plain console app deployed as a Scheduled WebJob. No need to use the SDK here. Just do what you need to do from your Main() and let it end.
I'd suggest #2 unless you have a specific need to use the WebJobs SDK.

Why does my Time trigger webjob keep running?

I have a Webjob that I want to be time triggered:
public class ArchiveFunctions
{
private readonly IOrderArchiver _orderArchiver;
public ArchiveFunctions(IOrderArchiver orderArchiver)
{
_orderArchiver = orderArchiver;
}
public async Task Archive([TimerTrigger("0 */5 * * * *")] TimerInfo timer, TextWriter log)
{
log.WriteLine("Hello world");
}
}
My program.cs:
public static void Main()
{
var config = new JobHostConfiguration
{
JobActivator = new AutofacJobActivator(RegisterComponents())
};
config.UseTimers();
var host = new JobHost(config);
// The following code ensures that the WebJob will be running continuously
host.RunAndBlock();
}
my publish-setting.json:
{
"$schema": "http://schemastore.org/schemas/json/webjob-publish-settings.json",
"webJobName": "OrdersArchiving",
"runMode": "OnDemand"
}
Here is what it looks like on azure portal:
My problem is that the job runs, I have the hello world, but the job keeps in run state and it get to a time out error message:
[02/05/2018 15:34:05 > f0ea5f: ERR ] Command 'cmd /c ""Ores.Contr ...' was aborted due to no output nor CPU activity for 121 seconds. You can increase the SCM_COMMAND_IDLE_TIMEOUT app setting (or WEBJOBS_IDLE_TIMEOUT if this is a WebJob) if needed.
What can I do to fix this?
I have a wild guess RunAndBlock could be a problem.. but I do not see a solution..
Thanks!
Edit:
I have tested Rob Reagan answer, it does help with the error, thank you!
On my same service, I have one other time triggerd job (was done in core, while mine is not).
You can see the Webjob.Missions is 'triggered', and status update on last time it ran. You can see as well the schedule on it.
I would like to have the same for mine 'OrdersArchiving'.
How can I achieve that?
Thanks!
Change your run mode to continuous and not triggered. The TimerTrigger will handle executing the method you've placed it on.
Also, make sure that you're not using a Free tier for hosting your WebJob. After twenty minutes of inactivity, the app will be paused and will await a new HTTP request to wake it up.
Also, make sure you've enabled Always On on your Web App settings to prevent the same thing from happening to a higher service tier web app.
Edit
Tom asked how to invoke methods on a schedule for a Triggered WebJob. There are two options to do so:
Set the job up as triggered and use a settings.json file to set up the schedule. You can read about it here.
Invoke a method via HTTP using an Azure Scheduler. The Azure Scheduler is a separate Azure service that you can provision. It has a free tier which may be sufficient for your use. Please see David Ebbo's post on this here.

Scheduled web job confusing about schedule

I have a web job that needs to run every day at 1am.
My settings.job is configured like this:
{
"schedule": "0 0 1 * * *",
"is_singleton": true
}
I have function declared in the Functions.cs
namespace Dsc.Dmp.SddUpgrade.WebJob
{
using System;
using System.IO;
using Microsoft.Azure.WebJobs;
public class Functions
{
public static void TriggerProcess(TextWriter log)
{
log.Write($"C# Timer trigger function executed at: {DateTime.Now}");
}
}
}
I am getting the following logs:
[09/28/2017 12:02:05 > 9957a4: SYS INFO] Status changed to Running
[09/28/2017 12:02:07 > 9957a4: INFO] No job functions found. Try making your job classes and methods public. If you're using binding extensions (e.g. ServiceBus, Timers, etc.) make sure you've called the registration method for the extension(s) in your startup code (e.g. config.UseServiceBus(), config.UseTimers(), etc.).
As I read the documentation, some people are using a function signature like this:
public static void TriggerProcess([TimerTrigger("0 0 1 * * *")] TimerInfo timerInfo, TextWriter log)
However, this does not seem logic to me, because a have already configured my web job to by scheduled in the settings.job.
What am I missing here?
If you use a settings.job file to schedule your WebJob, your logic should go in the Program.cs's Main function. You can ignore the Functions.cs file if you go this route. This is great for migrating a console app into a WebJob and scheduling it.
The TimerTrigger is a WebJob extension. It's useful because it's possible to have multiple methods in Functions.cs, each with a separate TimerTrigger that executes on a different schedule. To use these, your WebJob needs to be continuous.
You need to put your logic in Program.cs.
The runtime will run your WebJob by executing the executable, running the Main method in Program.cs.
You seem to be missing the [FunctionName("TriggerProcess")] attribute in the function definition, that´s why you´re getting the "job not found" error.

Azure subscription and webjob questions

So i'm trying to get a small project of mine going that I want to host on azure, it's a web app which works fine and I've recently found webjobs which I now want to use to have a task run which does data gathering and updating, which I have a Console App for.
My problem is that I can't set a schedule, since it is published to the web app which dosen't support scheduling, so I tried using the Azure Webjobs SDK and using a timer but it wont run without a AzureWebJobsStorage connection string which I cannot get since my Azure account is a Dreamspark account and I cannot make a Azure Storage Account with it.
So I was wondering if there is some way to get this webjob to run on a time somehow (every hour or so). Otherwise if I just upgraded my account to "Pay-As-You-Go"? would I still retain my free features? namely SQL Server.
Im not sure if this is the right palce to ask but I tried googling for it without success.
Update: Decided to just make the console app run oin a infinate loop and ill just monitor it through the portal, the code below is what I am using to made that loop.
class Program
{
static void Main()
{
var time = 1000 * 60 * 30;
Timer myTimer = new Timer(time);
myTimer.Start();
myTimer.Elapsed += new ElapsedEventHandler(myTimer_Elapsed);
Console.ReadLine();
}
public static void myTimer_Elapsed(object sender, ElapsedEventArgs e)
{
Functions.PullAndUpdateDatabase();
}
}
The simplest way to get your Web Job on a schedule is detailed in Amit Apple's blog titled "How to add a schedule to a triggered WebJob".
It's as simple as adding a JSON file called settings.job to your console application and in it describing the schedule you want as a cron expression like so:
{"schedule": "the schedule as a cron expression"}
For example, to run your job every 30 minutes you'd have this in your settings.job file:
{"schedule": "0 0,30 * * * *"}
Amit's blog also goes into details on how to write a cron expression.
Caveat: The scheduling mechanism used in this method is hosted on the instance where your web application is running. If your web application is not configured as Always On and is not in constant use it might be unloaded and the scheduler will then stop running.
To prevent this you will either need to set your web application to Always On or choose an alternative scheduling option - based on the Azure Scheduler service, as described in a blog post titled "Hooking up a scheduler job to a WebJob" written by David Ebbo.

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