I have looked through documentation for WebJobs, Functions and Logic Apps in Azure but I cannot find a way to schedule a one-time execution of a process through code. My users need to be able to schedule notifications to go out at a specific time in the future (usually within a few hours or a day from being scheduled). Everything I am reading on those processes is using CRON expressions which is not designed for one-time executions. I realize that I could schedule the job to run on intervals and check the database to see if the rest of the job needs to run, but I would like to avoid running the jobs unnecessarily if possible. Any help is appreciated.
If it is relevant, I am using C#, ASP.NET MVC Core, App Services and a SQL database all hosted in Azure. My plan was to use Logic apps to check the database for a scheduled event and send notifications through Twilio, SendGrid, and iOS/Android push notifications.
One option is to create Azure Service Bus Messages in your App using the ScheduledEnqueueTimeUtc property. This will create the message in the queue, but will only be consumable at that time.
Then a Logic App could be listening to that Service Bus Queue and doing the further processing, e.g. SendGrid, Twilio, etc...
HTH
You could use Azure Queue trigger with deferred visibility. This will keep the message invisible for a specified timeout. This conveniently acts as a timer.
CloudQueue queueOutput; // same queue as trigger listens on
var strjson = JsonConvert.SerializeObject(message); // message is your payload
var cloudMsg = new CloudQueueMessage(strjson);
var delay = TimeSpan.FromHours(1);
queueOutput.AddMessage(cloudMsg, initialVisibilityDelay: delay);
See https://learn.microsoft.com/en-us/dotnet/api/microsoft.azure.storage.queue.cloudqueue.addmessage?view=azure-dotnet for more details on this overload of AddMessage.
You can use Azure Automation to schedule tasks programmatically using REST API. Learn about it here.
You can use Azure Event Grid also. Based on this article you can “Extend existing workflows by triggering a Logic App once there is a new record in your database".
Hope this helps.
The other answers are all valid options, but there are some others as well.
For Logic Apps you can build this behavior into the app as described in the Scheduler migration guide. The solution described there is to create a logic app with a http trigger, and pass the desired execution time to that trigger (in post data or query parameters). The 'Delay Until' block can then be used to postpone the execution of the following steps to the time passed to the trigger.
You'd have to change the logic app to support this, but depending on the use case that may not be an issue.
For Azure functions a similar pattern could be achieved using Durable Functions which has support for Timers.
Related
I have an Azure function processing a file uploaded by end user which could take a long time. I'd like to notify the end user when process is completed. I'm not clear whether Azure event grid topic, event hub, service bus or other services would be best for this?
I'd like the user to be able to register how they would like to get notified as well. Is there an Azure service that would accomodate this?
You can use Azure Logic Apps to run your functions at a specific time and notify end users by email when finished for instance. Azure Logic Apps are used to run automated workflows that integrate your apps, data, services, and systems.
Link that could be helpful: Create and run your own code from workflows in Azure Logic Apps by using Azure Functions
You can use Signal R service by Azure. It will be useful in case you want to notify user on any real-time update from the server.
you can refer Signal R using Azure Function to implement it with azure function.
I'm migrating extensive SharePoint application to Azure and I'm looking for a recommendation in terms of replacing Timer Jobs with some Azure service. Which one would be most suitable? Azure Functions, Azure Logic Apps? The timer job needs to connect to a web service and make some GET / POST calls. Maybe sending e-mails.
What would you recommend? Any pros / cons?
Thanks,
George
With that additional context, but without a full understanding of the logic you need to implement around the calls, I'd suggest you look into a combination of a Logic App and a Function. The Logic App will make the time trigger and any email jobs more configurable, but the Function will give you more control of your web requests and logic, especially if those are more complex than simply making a request and ensuring it succeeded.
Set up the Logic App on a time trigger, and use it to orchestrate the Function and any email jobs. You can use the Logic App HTTP connector to trigger an HTTP-based Function, or you can look at the Function App connector.
For the Function, write it in C# and reuse your code there. Add any other calls and handling logic you require, then return a response for the Logic App to consume.
Add Control and Email (there are several of these for different email providers) connectors to the Logic App to send out relevant emails per the Function app result.
I am looking for a simple Scheduler to execute a task inside my Java web application deployed in Azure cloud. I am evaluating Azure functions with TimerTrigger for my requirement. Here, I am planning to define a Azure function with a callback API URL to invoke my application for executing the task inside my application.
I have some queries in this approach. Can anyone help me If you are familiar with Azure functions please?
1) Is it possible to initiate/reschedule/cancel a Azure TimerTrigger function from a Java application through API at runtime?
2) If yes, Is it possible to pass a call back URL to the timer Trigger?
3) Is there any known drawback in using Azure functions?
Thanks!
TimerTriggers don't have an api to control this (you could try to hack one in by uploading a new function.json with the schedule you want and whether or not the timer is disabled, but I don't recommend that at all).
Instead, I'd suggest using a QueueTrigger. This would allow you to pass the function any data you need in the queue item (the callback url) and you could add items to the queue with a visibility timeout in order to create your schedule. If you need to cancel pending executions, just remove the item(s) from the queue. The function is also more durable - if a queue item fails, it will automatically retry (unlike timers).
3) is way too broad of a question to have an answer.
For my new project every component is going to be deployed in Azure. I have a 3rd party application that processes events using RabbitMQ and I want to subscribe to these events and process them to store the data in the events in my own database.
What would be the best way to go? Using webjobs and Writing my own Custom Trigger/ Binder for RabbitMQ?
Thanks for the advice in advance
Based on your requirement, I assume that Azure WebJob is an ideal approach to achieve your purpose. In that case, you could use a WebJob as a consumer client to subscribe the events and process the data. Please try to create a WebJob and following the link provided by Mitra to subscribe the event and implement your logic processes in the WebJob.
Please pay attention that WebJob run as background processes in the context of an Azure Web App. In order to keep your WebJob running continuously, you need to be running in standard mode or highly and enable the "Always On" setting.
Consideration of scaling, you could use the Azure Websites scale feature to scale extra WebJobs instances. For scaling, you could refer to this tutorial.
For having subscription based routing, you can use Topics in Rabbitmq. Using topics you can push events to specific queues and then consumers at those queues can do processing to write data into the database. The only thing to take care of is to have a correct routing key for each queue.
That way you can have subscription based mechanism. The only thing with this approach will be that for each event there will be one queue.
The benefit of having one queue per event is it will be easy to keep track of events and so easy debugging.
If the number of events are very large then you can have only one queue but after consuming the message you have to trigger the event.
Here is the link for the reference:
https://www.rabbitmq.com/tutorials/tutorial-five-python.html
I'm simply trying to work out how best to retrieve messages as quickly as possible from an Azure Service Bus Queue.
I was shocked that there wasn't some way to properly subscribe to the queue for notifications and that I'm going to have to poll. (unless I'm wrong in which case the documentation is terrible).
I got long polling working, but checking a single message every 60 seconds looks like it'll cost around £900 per month (again, unless I've misunderstood that). And if I add a redundant/second service to poll it'll double.
So I'm wondering what the best/most cost efficient way of doing it is.
Essentially I just want to take a message from the queue, perform an API lookup on some internally held data (perhaps using hybrid services?) and then perhaps post a message back to a different queue with some additional information .
I looked at worker roles(?) -- is that something that could do it?
I should mention that I've been looking at doing this with node.js.
Check out these videos from Scott Hanselman and Mark Simms on Azure Queues.
It's C# but you get the idea.
https://channel9.msdn.com/Search?term=azure%20queues%20simms#ch9Search
Touches on:
Storage Queues vs. Service Bus Queues
Grabbing messages in bulk vs. one by one (chunky vs. chatty)
Dealing with poison messages (bad actors)
Misc implementation details
Much more stuff i can't remember now
As for your compute, you can either do a VM, a Worker Role (Cloud Services), App Service Webjobs, or Azure Functions.
The Webjobs SDK and Azure Functions bot have a way to subscribe to Queue events (notify on message).
(Listed from IaaS to PaaS to FaaS - Azure Functions - if such a thing exists).
Azure Functions already has sample code provided as templates to do all that with Node. Just make a new Function and follow the wizard.
If you need to touch data on-prem you either need to look at integrating with a VNET that has site-to-site connectivity back to your prem, or Hybrid Connections (App Service only!). Azure Functions can't do that yet, but every other compute is a go.
https://azure.microsoft.com/en-us/documentation/articles/web-sites-hybrid-connection-get-started/
(That tutorial is Windows only but you can pull data from any OS. The Hybrid Connection Manager has to live on a Windows box, but then it acts as a reverse proxy to any host on your network).
To deal with Azure ServiceBus Queue easily, the best option seems to be Azure Webjob.
There is a ServiceBusTrigger that allows you to get messages from an Azure ServiceBus queue.
For node.js integration, you should have a look at Azure Function. It is built on top of the webjob SDK and have node.js integration :
Azure Functions NodeJS developer reference
Azure Functions Service Bus triggers and bindings for queues and topics
In the second article, there is an example on how get messages from a queue using Azure Function and nodejs :
module.exports = function(context, myQueueItem) {
context.log('Node.js ServiceBus queue trigger function processed message', myQueueItem);
context.done();
};