Azure Virtual Machine Scale Sets (VMSS) let you deploy and manage a group of identical, load-balanced virtual machines. They help you build scalable and highly available applications by automatically increasing or decreasing the number of VMs based on demand.
What Are VM Scale Sets?
VM Scale Sets are a form of Infrastructure as a Service (IaaS) that:
- Deploy up to 1,000 VM instances from a shared configuration.
- Are easy to create and manage.
- Require no extra cost beyond the virtual machines, managed disk storage, and load balancer.
Why Use VM Scale Sets?
VMSS is perfect for running applications across multiple identical VMs. If one instance fails, traffic is automatically rerouted to others, ensuring high availability. This setup is ideal for web apps, microservices, or custom workloads.
VM Scale Sets support:
- Automatic scaling: Increase or decrease VMs based on traffic or a schedule.
- Manual scaling: Adjust the number of instances when you choose.
- Upgrade modes: Choose between automatic, manual, or rolling upgrades (which update VMs in batches).
For related information on autoscaling and elasticity, go to AZ-900: Describe the benefits of high availability and scalability in the cloud.
High Availability Options
VM instances in a scale set can use:
- Availability Zones to spread instances across multiple data centers in a region.
- Availability Sets to protect against localized hardware failures.
These features help you meet uptime requirements and support disaster recovery plans. See AZ-900: Describe Redundancy options for more details.
Monitoring and Maintenance
You can manage and monitor VM Scale Sets using:
- Azure Monitor for VMs for performance metrics and alerts.
- Application Insights for detailed application-level telemetry.
These tools ensure you stay informed about system health and performance. To explore monitoring further, refer to #56#.
Conclusion
Azure Virtual Machine Scale Sets give you the power to create reliable and scalable cloud services. Whether you’re handling variable workloads or planning for resilience, VMSS adapts to your needs.
Want to build scalable infrastructure the smart way? Watch our AZ-900 video course and see how VM Scale Sets work in practice – or go back to the topics in the AZ-900 exam.
Please click here to find out more about Microsoft’s AZ-900 exam.
