I am trying to find a way to run some code one time (where I set connection strings, DI, and other configs) when my Azure function starts. So right now, it calls a Run method as the entrypoint with this in the generated function.json:
"entryPoint": "MyFunctionApp.MessageReceiver.Run"
This Run method uses an EventHubTrigger and processes incoming messages like so:
[FunctionName("MessageReceiver")]
public static void Run([EventHubTrigger("eventHubName", Connection = "eventHubConnection")]string message, TraceWriter log)
{
if (string.IsNullOrWhiteSpace(message))
{
log.Info($"C# Event Hub trigger function processed a message: {message}");
}
}
Is there a way that I can run some code on the initial startup before this Run method is called? Or is there a way to declare an entrypoint that I can call before this class and then call Run() and somehow pass in the trigger? I am trying to find a way that avoids hackish stuff like setting boolean properties to see if the app has started.
You can implement an IExtensionConfigProvider. Those will be scanned and execute on "Startup".
using Microsoft.Azure.WebJobs.Host.Config;
namespace MyFunctionApp
{
public class Startup : IExtensionConfigProvider
{
public void Initialize(ExtensionConfigContext context)
{
// Put your intialization code here.
}
}
}
At the 2019 Build conference, Microsoft released the functionality to have a callable method when the Azure Function app starts up. This can be used for registering DI classes, creating static DB connections, etc.
The documentation for these new features can be found at Azure Function Dependency Injection
Related
I have an issue with Azure Function Service Bus trigger.
The issue is Azure function cannot wait a message done before process a new message. It process Parallel, it not wait 5s before get next message. But i need it process sequencecy (as image bellow).
How can i do that?
[FunctionName("HttpStartSingle")]
public static void Run(
[ServiceBusTrigger("MyServiceBusQueue", Connection = "Connection")]string myQueueItem,
[OrchestrationClient] DurableOrchestrationClient starter,
ILogger log)
{
Console.WriteLine($"MessageId={myQueueItem}");
Thread.Sleep(5000);
}
I resolved my problem by using this config in my host.json
{
"version": "2.0",
"extensions": {
"serviceBus": {
"messageHandlerOptions": {
"maxConcurrentCalls": 1
}
}
}}
There are two approaches you can accomplish this,
(1) You are looking for Durable Function with function chaining
For background jobs you often need to ensure that only one instance of
a particular orchestrator runs at a time. This can be done in Durable
Functions by assigning a specific instance ID to an orchestrator when
creating it.
(2) Based on the messages that you are writing to Queue, you need to partition the data, that will automatically handle the order of messages which you do not need to handle manually by azure function
In general, ordered messaging is not something I'd be striving to implement since the order can and at some point will be distorted. Saying that, in some scenarios, it's required. For that, you should either use Durable Function to orchestrate your messages or use Service Bus message Sessions.
Azure Functions has recently added support for ordered message delivery (accent on the delivery part as processing can still fail). It's almost the same as the normal Function, with a slight change that you need to instruct the SDK to utilize sessions.
public async Task Run(
[ServiceBusTrigger("queue",
Connection = "ServiceBusConnectionString",
IsSessionsEnabled = true)] Message message, // Enable Sessions
ILogger log)
{
log.LogInformation($"C# ServiceBus queue trigger function processed message: {Encoding.UTF8.GetString(message.MessageId)}");
await _cosmosDbClient.Save(...);
}
Here's a post for more detials.
Warning: using sessions will require messages to be sent with a session ID, potentially requiring a change on the sending side.
I have a web job that needs to run every day at 1am.
My settings.job is configured like this:
{
"schedule": "0 0 1 * * *",
"is_singleton": true
}
I have function declared in the Functions.cs
namespace Dsc.Dmp.SddUpgrade.WebJob
{
using System;
using System.IO;
using Microsoft.Azure.WebJobs;
public class Functions
{
public static void TriggerProcess(TextWriter log)
{
log.Write($"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.
Trying to get Azure Webjobs to react to incoming Service Bus event, Im running this by hitting F5. Im getting the error at startup.
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.).
My functions-class look like this:
public class Functions
{
// This function will get triggered/executed when a new message is written
// on an Azure Queue called queue.
public static void ProcessQueueMessage([ServiceBusTrigger("test-from-dynamics-queue")] BrokeredMessage message, TextWriter log)
{
log.WriteLine(message);
}
}
I have every class and method set to public
I am calling config.UseServiceBus(); in my program.cs file
Im using Microsoft.Azure.WebJobs v 1.1.2
((Im not entirely sure I have written the correct AzureWebJobsDashboard- and AzureWebJobsStorage-connectionstrings, I took them from my only Azure storage-settings in Azure portal. If that might be the problem, where should I get them ))
According to your mentioned error, it seems that you miss parameter config for ininitializing JobHost. If it is that case, please use the following code.
JobHost host = new JobHost(config)
More detail info about how to use Azure Service Bus with the WebJobs SDK please refer to the document.The following is the sample code from document.
public class Program
{
public static void Main()
{
JobHostConfiguration config = new JobHostConfiguration();
config.UseServiceBus();
JobHost host = new JobHost(config);
host.RunAndBlock();
}
}
My Azure WebJob used to run in the VS2015 Debugger, but I found it gradually became very intermittent and now won't run at all. It works fine it I deploy it to Azure. The job is marked as RunOnStartUp.
public class Program
{
static void Main()
{
var config = new JobHostConfiguration();
config.UseTimers();
var host = new JobHost(config);
host.RunAndBlock();
}
}
public class TestJob : BaseJob
{
public static async Task StartupJob([TimerTrigger("05:00:00", RunOnStartup = true)] TimerInfo timerInfo, TextWriter log)
{
log.WriteLine("StartupJob");
await Jobs.Test(some params);
log.WriteLine("Sorted");
}
}
What do I need to do to get it running in the Debugger?
I'm guessing you use the same storage account for your job in Azure and when you debug it locally? If that's the case - the TimeTrigger runs as a singleton which means it needs to acquire a lock to be able to execute. If your webjob is already running in Azure your local version, which you're trying to debug, is not able to acquire the lock.
To avoid this just use different storage accounts for "live" Azure version and local local development.
I would also recommend to enable "development settings" - config.UseDevelopmentSettings(); - when you debug locally. If you enable it you'll see the messages "unable to acquire lock for function..." (or something similar).
See Jason Haley's comment in this thread:
(total hack but should work) rename the function while debugging so
the lock listener blob name will be different.
This hack worked for me. Maybe to make it less hacky, you could use the Disable-attribute to create a timer-triggered function that would only be enabled in your local environment:
Create "MyFunction", which handles the logic. This is the one that will run in your Azure app. Note RunOnStartup=false as recommended by the docs.
[FunctionName("MyFunction")]
public async Task RunJob(
[TimerTrigger("0 0 0 * * *", RunOnStartup = false)] TimerInfo timer)
{
//logic here
}
Create "MyFunction-Local" with the Disable attribute and a different method name. All this does is call the method above.
[FunctionName("MyFunction-Local")]
[Disable("Disable_MyFunction")]
public async Task RunJobLocal(
[TimerTrigger("0 0 0 * * *", RunOnStartup = true)] TimerInfo timer)
{
RunJob(timer);
}
In your local app configuration, set {"Disable_MyFunction" = false}, whereas for the app running in Azure, set this to true.
I'm trying to gain some understanding and experience in creating background processes on Azure.
I've created a simple console app and converted it to Azure Worker Role. How do I invoke it? I tried to use Azure Scheduler but looks like the scheduler can only invoke a worker role through message queues or HTTP/HTTPS.
I never thought about any type of communication as my idea was to create a background process that does not really communicate with any other app. Do I need to convert the worker role to a web role and invoke it using Azure Scheduler using HTTP/HTTPS?
Worker role has three events:
OnStart
OnRun
OnStop
public class WorkerRole : RoleEntryPoint
{
ManualResetEvent CompletedEvent = new ManualResetEvent(false);
public override void Run()
{
//Your background processing code
CompletedEvent.WaitOne();
}
public override bool OnStart()
{
return base.OnStart();
}
public override void OnStop()
{
CompletedEvent.Set();
base.OnStop();
}
}
The moment you run/debug your console converted worker role. First two (OnStart & OnRun) fires in sequence. Now in OnRun you have to keep the thread alive, either by using a while loop or using ManualResetEvent this is where your background processing code would live.
OnStop is fired when you either release the thread from OnRun or something un-expected goes. This is the place to dispose your objects. Close unclosed file-handles database connection etc.