Cloud Fundamentals
/Intermediate
Auto Scaling (ASG / VMSS / MIG)
Definition
A cloud feature that automatically adds (scales out) or removes (scales in) compute instances based on live user traffic, CPU usage, or predefined schedules.
Explain Like I'm New
The ultimate thermostat for servers. If 10,000 users log in, the system automatically buys 5 more servers. When the users leave, it instantly deletes the 5 servers so you stop paying for them.
Real World Example
AWS Auto Scaling Groups, Azure VM Scale Sets, GCP Managed Instance Groups. On Black Friday, an e-commerce site experiences a 500% traffic spike. The Auto Scaler detects high CPU usage and automatically clones the web server 20 times to prevent the site from crashing.
Common Use Cases
- •Handling traffic spikes
- •Cost optimization
- •High availability
Interview Questions
basic
- What is 'Scaling Out' versus 'Scaling In'?
intermediate
- What is the difference between Horizontal Scaling and Vertical Scaling?