Cloud Architecture Patterns

Chapter 4. Auto-Scaling Pattern

This essential pattern for automating operations makes horizontal scaling more practical and cost-efficient.

Scaling manually through your cloud vendor’s web-hosted management tool helps lower your monthly cloud bill, but automation can do a better job of cost optimization, with less manual effort spent on routine scaling tasks. It can also be more dynamic. Automation can respond to signals from the cloud service itself and scale reactively to actual need.

The two goals of auto-scaling are to optimize resources used by a cloud application (which saves money), and to minimize human intervention (which saves time and reduces errors).

Context

The Auto-Scaling Pattern is effective in dealing with the following challenges:

• Cost-efficient scaling of computational resources, such as web tier or service tier.

• Continuous monitoring of fluctuating resources is needed to maximize cost savings and avoid delays.

• Frequent scaling requirements involve cloud resources such as compute nodes, data storage, queues, or other elastic components.

This pattern assumes a horizontally scaling architecture and an environment that is friendly to reversible scaling. Vertically scaling (by changing virtual machine size) is also possible, although is not considered in this pattern.

Cloud Significance

Cloud platforms, supporting a full range of resource management, expose rich automation capabilities to customers. These capabilities allow reversible scaling and make it highly effective when ...