Difference between Scale Sets and Load Balanced Sets for Azure VM

Question

_{Tuesday, December 1, 2015 1:35 PM}

Hi All,

Wanted to know the difference between Scale Sets and Load Balanced Sets for Azure VM.

Regards,

Saurabh

All replies (2)

_{Tuesday, December 1, 2015 1:51 PM ✅Answered}

Hi,

It's simple:

1- Load Balancing:

Load Balancing (Via creating Load Balanced sets on Azure) is distributing several connections between running servers. The servers are always running and are processing requests.

2- Scale Sets

Scale sets is a new feature (along side with teh existing Autosacale feature). It's used to support more and more workloads on a farm. Scale sets will permit you to start/stop VMs depending on your running VMs usage/Performance.

Example : You create 3 VMs which are load balanced (Yes). Then you will define scale sets and configure them to start/stop the third VM if the total CPU exceeds 90 %. When the total CPU usage exceeds 90% the third VM will start, and because it's included on the load balanced farm, it will process requests. When the load decrease, the VM will be stopped and so on

Regards, Samir Farhat || Datacenter Consultant || The way to share my knowledge with the community Visit my blog : buildwindows.wordpress.com buildwindows.wordpress.com </a>

_{Tuesday, December 1, 2015 7:27 PM ✅Answered}

Scale sets is a new (first class citizen) resource we have within the compute resource provider in Azure. The feature is currently in preview and can remind you you a bit of the good old "worker role" we used to have to the PaaS v1 model.

However, the PaaS v1 model was limited to Windows machines only - while scale sets can leverage any available image you prefer to use.

Also, if you look under the hood you can see that the scale sets are the IaaS backend that enables and simplifies PaaS resources, such as Service Fabric, Containers, Batch and more.

When provisioning a scale set, you are actually making a single call to the underlying resource provider that instantiates the set, and also let you manage the VMs as a single unit.

Since scale sets are supposed to scale (autoscale it is) you can of course integrate with load balancing, as Samir explained in his answer. 

Here's an Azure Resource Manager template that will provision a VM Scale Set and use DSC extension to provision and configure IIS.

https://github.com/krnese/AzureDeploy/tree/master/VMScaleSets

Kristian (Virtualization and some coffee: http://kristiannese.blogspot.com )