Auto Scaling
Auto scaling is the automatic addition or removal of compute capacity, such as virtual machines, containers or pods, in response to load metrics or schedules, keeping applications responsive while avoiding payment for idle resources.
Auto scaling automatically adjusts the amount of compute capacity assigned to an application in response to demand. Horizontal scaling adds or removes instances, containers or pods, while vertical scaling changes the CPU and memory of existing ones. Scaling policies are driven by metrics such as CPU utilisation, request rate or queue length, by schedules for predictable peaks, or by forecasts in predictive scaling. Minimum and maximum limits bound how far capacity can change.
Cloud services include Amazon EC2 Auto Scaling, Azure Virtual Machine Scale Sets and Google Cloud managed instance groups. In Kubernetes, the Horizontal Pod Autoscaler scales pods while a cluster autoscaler adds or removes nodes. Auto scaling keeps services responsive during traffic spikes and reduces costs by releasing idle capacity at quiet times, which is central to the elasticity that distinguishes cloud from fixed on-premise capacity.
Applications must be designed for it: instances should be stateless, start quickly and shut down cleanly. Poorly chosen metrics or thresholds cause oscillation, and scaling lags behind sudden surges because new capacity takes time to boot, so warm pools or spare headroom are used for latency-sensitive services. Maximum limits and budget alerts prevent runaway costs from faulty code or malicious traffic.
Key points
- Horizontal scaling changes instance count; vertical scaling changes instance size
- Policies use metrics such as CPU, request rate or queue depth, or fixed schedules
- Kubernetes uses the Horizontal Pod Autoscaler and a cluster autoscaler
- Applications should be stateless and start quickly to scale well
Where AiVibe comes in
AiVibe Software Services delivers cloud solutions on AWS, Microsoft Azure, Google Cloud or on-premise, together with cloud security, legacy modernisation, data analytics and AI and machine learning services.
Related terms
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- KubernetesCloud & AI Infrastructure
- Serverless ComputingCloud & AI Infrastructure
- FinOps (Cloud Financial Operations)Cloud & AI Infrastructure
- High Availability (HA)Cloud & AI Infrastructure
- ObservabilityCloud & AI Infrastructure