AZR - Virtual Machine Scale Set

(Azure Scale Set is like Autoscaling group in AWS)

Azure virtual machine scale sets enable you to create and manage a group of identical, load-balanced VMs. The number of VM instances can automatically increase or decrease in response to demand or a defined schedule.
Scale sets provide high availability to your applications and allow you to centrally manage, configure, and update a large number of VMs.
With virtual machine scale sets, you can build large-scale services for areas such as compute, big data, and container workloads.


Why Scale Set

• Easy to create & maintain multiple VMs: Easy scaling of hundreds of VMs because all created by the same OS image.
• Networking: Uses 'Load Balancers' with Basic layer-4 traffic distribution and 'Azure Application Gateway' with advanced layer-7 traffic distribution.
• Load Balancers: Used for IP/port based mapping with VMs
• Azure Application Gateway: Used for URL based mapping with VMs

• Provides high availability and application resiliency: With the help of multiple VMs using Availability set or Availability zones.
• Support Spot Instances: You can set Spot price that is a maximum price per hour US $ you want to pay for an instance. Azure allot instance if your set price is greater than the platform price at that time.

• Auto Scaling: Provide auto scaling

• Large Scale handling: 
• Scale sets support up to 1,000 VM instances. If you create and upload your own custom VM images, the limit is 600 VM instances. 
• For the best performance with production workloads, use Azure Managed Disks.
• Support additional disk for VMs

Features

1. Control it like IaaS, scale it like PaaS: Deploy Virtual Machine Scale Sets using Azure Resource Manager (ARM) templates with support for Windows and Linux platform images, as well as custom images and extensions.
2. Run Cassandra, Cloudera, Hadoop, MongoDB, and Mesos
3. Quickly scale your big compute and big data applications
4. Attach additional data disks as per your application requirement