Azure Spot Instances

Azure Spot Instances provide a cost-effective way to run workloads by taking advantage of unused capacity in Azure. They offer significant cost savings compared to pay-as-you-go prices but come with the risk of eviction when Azure needs the capacity back.

Overview

Azure Spot Instances allow you to take advantage of unused Azure capacity at a discounted rate. They are ideal for workloads that can tolerate interruptions, such as batch processing, dev/test environments, and large-scale stateless applications.

Core Functionality

  • Pricing Model: Save up to 90% compared to pay-as-you-go prices by using unused capacity.
  • Eviction Policy: Spot VMs can be evicted based on capacity needs or if the maximum price you set is exceeded. Eviction can occur with as little as 30 seconds’ notice.
  • No SLA: Spot Instances do not come with an SLA, meaning there is no guaranteed uptime.
  • Capacity Availability: Availability of Spot Instances varies based on region, time of day, and other factors.

Well-Architected Framework

Operational Excellence

  • Automation: Use Azure Automation to manage and monitor Spot Instances, ensuring they are efficiently utilized and automatically redeployed if evicted.
  • Monitoring: Implement Azure Monitor to track the performance and availability of Spot Instances, setting up alerts for eviction events.

Security

  • Network Security: Apply Network Security Groups (NSGs) to control inbound and outbound traffic to Spot Instances.
  • Identity Management: Use Azure Active Directory (AAD) for secure access and identity management.

Reliability

  • Redundancy: Design your architecture to handle the eviction of Spot Instances by using redundant instances or fallback to standard VMs.
  • Data Persistence: Ensure data is stored in persistent storage solutions like Azure Blob Storage or Azure Managed Disks to prevent data loss during evictions.

Performance Efficiency

  • Scaling: Use Azure Virtual Machine Scale Sets to automatically scale Spot Instances based on demand and availability.
  • Optimization: Continuously monitor and optimize the performance of Spot Instances to ensure they meet workload requirements.

Cost Optimization

  • Budgeting: Set maximum prices for Spot Instances to control costs and avoid unexpected expenses.
  • Utilization: Regularly review and adjust the usage of Spot Instances to maximize cost savings.

Sustainability

  • Resource Efficiency: Use Spot Instances to make efficient use of Azure’s unused capacity, reducing the overall environmental impact.
  • Energy Consumption: Monitor and optimize the energy consumption of your workloads running on Spot Instances.

References


Last modified February 19, 2025: Update azure-point-to-site-vpn.md (a9c807a)