Azure Cloud Service scaling time frame?

Question

I'm planning to move our web site to Windows Azure and run it has a Cloud Service / Web Role. I have run some load testing and it works ok but at the moment i have some issues with the scaling features.

When i run a load test for an hour or so i see that our instance CPU is going up to 90% more or less right away. I have enabled auto-scale but it takes a looooonnngg time before Azure actually add a new instance. I think i read somewhere that the CPU metrics it used is based on 45 minutes of load and that seems kind of useless if your CPU has to run on 90% for 45 minutes before it actually scales up? Can i change this time frame somewhere?

Answer 1

From an Azure Chat log on autoscaling, I see that "By default, autoscale takes the average CPU over 45 minutes – this means it could be 30+ min after a spike. But, with the Azure SDK, you can manually set different time periods to average metrics over."

• Source: http://azure.microsoft.com/blog/2013/12/06/recap-azurechat-virtual-machines-and-autoscaling/

The above comment provides a link to the following:

• Azure Monitoring Services: https://www.nuget.org/packages/Microsoft.WindowsAzure.Management.Monitoring/0.9.0-preview

Also, here's a comment from a StackOverflow post, related to the 45-minute threshold: "And by the way, 45 minutes is the default time needed for an auto-scale action to occur for cloud services. You can change this using the management API's. I talk about this and how to do it in my blog."

• Source: https://stackoverflow.com/questions/25434638/azure-autoscaling-is-not-working#comment39685701_25436005

In the above comment, the blog link specified is: http://rickrainey.com/2013/12/15/auto-scaling-cloud-services-on-cpu-percentage-with-the-windows-azure-monitoring-services-management-library/

Hope that helps!