I am building the Multi Tenancy Web Application that has long running task. This task will take more CPU/RAM:
- Read list of employee by Tenant from Azure SQL.
- Use
Parallel.ForEachto perform multi task per employee list. - Long running calculating per employee (each employee is one task).
- Save employee data to Azure SQL.
- Push notification to client browser.
The Web Application will be deployed on Azure App Service. The task will take more time to complete (about 30 minutes and more). If 2 users from 2 tenants perform the task at the same time, there will be insufficient server resources(CPU/RAM). If I have 100 or more tenants, things get worse.
There is one solution, the tenant who comes in later will have to wait for the previous tenant's task to complete. However, it is certain that the customer will not agree.
So my question: Is there any Azure service I can use to run this long-running process where tenants will not have to wait for each other? Or can give me a solution for this? The Azure App Service scale out feature is one of the solution, isn't it?
Yes, You can make use of Azure App service scale out feature, To Scale your app according to the load. If users from multiple tenants are performing the task. The Web app will automatically scale based on the load and the rule you have configured in the Auto scale feature.
There are two ways to configure the auto scaling. Auto-scale and Automatic scaling. In auto scale you provide the rules on based on which the App instances are scaled out and Automatic Scaling feature is in preview it scales out your app based on the behaviour of your web app.
Manually scale your instances like below:-
Auto-scale like below:-
For enabling Automatic scaling which I'd recommend for your workload, You need to have your App service in Premium plan. If you enable Automatic scaling you are not required to have Auto scaling rule like above, Automatic scaling will scale your app automatically based on its behaviour.
You can configure Always ready instance these are the instances which are running and ready to serve the requests when required. Maximum burst is the number of instances the app can be scaled out to.
Along with Scale out feature you can make use of Webjobs to run the long running tasks in the background, Web jobs will use the same instances of app service your Web app is running on:-
Method 2)
One more method is to use Azure batch service to run your long running task.
Refer this .Net API example to run long running task using Azure Batch service.