Azure Traffic manager with more than one Web App in the same region

2
votes

I'd need to use Traffic Manager to route traffic to three app services I have in the same region (one app service with three instances won't work, I need more control on the load balancing).

I read here that this is possibile

I tried to set up the app services in different app service plans but still I cannot assign the same domain to more than one app service. In the doc I read "scale unit" but I do not know what it is, any ideas? Basically I cannot create two App Services in the same region with the same domain assigned to them.

1
azureazure-virtual-network
When they talk about scale units I think they are talking about the VMs that run Azure App Service. You can see the URL of the scale unit if you run nslookup yoursite.azurewebsites.net. You will get an answer like waws-prod-am2-077.vip.azurewebsites.windows.net. That means the Web Apps can't be in the same App Service Plan. – juunas
Instead of multiple App Service Plans in the same Region, you should use manual scaling or Autoscale to have Multiple Instances of your app in the Region. – Chris Pietschmann
Stack Overflow is a site for programming and development questions. This question appears to be off-topic because it is not about programming or development. See What topics can I ask about here in the Help Center. Perhaps Super User or Unix & Linux Stack Exchange would be a better place to ask. Also see Where do I post questions about Dev Ops? – jww

1 Answers

5
votes

I am not really sure that you need more App Service Plans, but let's say you need.

Than what you will be looking at is nested profiles.

There is also good documentation which explains the limitations:

Each Traffic Manager profile can have at most one Web App endpoint from each Azure region. To work around for this constraint, you can configure a Web App as an External endpoint. For more information, see the FAQ.

and workarounds for some of them here.

The scale unit, is the one that bugs you. @juunas is on the correct path to help you find your scale unit. However AppServicePlan is not a single VM, but that's another subject.

So the basic idea:

  • you create an app service plan
  • you create a web app within it
  • you rung the nslookup yoursite.azurewebsites.net to discover your real DNS name. Just like @juunas pointed, it would be something like waws-prod-am2-077.vip.azurewebsites.windows.net. The waws-prod-am2-077 is your scale unit.

You repeat these steps until you discover that your App Service Plans run on different scale units.

It is really pity that this is not documented anywhere. And no, there is no easier way to check the scale unit of an app service plan. Neither is there easier way to deploy multiple app service plans across different scale units.

On the other hand, having your app service plans spread across different scale units will give your app much better resiliasncy against partial service outages :)