What are Azure Virtual Machine Scale Sets?
Azure Virtual Machine Scale Sets provide a scalable way to run applications on a set of VMs. When deployed, the VMs in a scale set can all have the same configuration and run the same applications or have different configurations and run different applications.
- As demand grows, the number of VMs running in the scale set increases.
- As demand goes down, the number of VMs running in the scale set decreases.
Virtual Machine Scale Sets are ideal for scenarios that include compute workloads, big-data workloads, and container workloads.
Virtual Machine Scale Sets are intelligent enough to automatically scale up or down the number of VM instances. The criteria used to activate the upscaling or downscaling can depend on a customized schedule, or on actual demand and usage. Scale sets can apply the same configuration to a group of VMs simultaneously. They don't require you to manually configure instances individually if you don't want to.
A scale set uses a load balancer to distribute requests across the VM instances. It uses a health probe or the Application Health Extension to determine the availability of each instance.
- If the instance responds, the scale set knows the instance is still available.
- If the instance fails to respond, the scale set knows the instance is unavailable and doesn't send requests to it.
Virtual Machine Scale Sets support both Linux and Windows VMs in Azure. If you deal with large workloads with varying and unpredictable demands, scale sets are a great solution because they automatically provide a highly available and scalable environment.