Scalability & High Availability

Table of Contents

Scalability #

Scalability means that an application / infrastructure can handle greater loads by adapting.

Vertical Scalability
- Increasing the size of an instance
- Very common for non-distributed systems, i.e. Databases
- Hardware limits apply
Horizontal Scalability (Elasticity)
- Increasing the number of instances
- Implies Distributed Systems
- Very common for web applications or modern applications
- Auto Scaling Groups
- For Horizontal Scaling (increasing the number of instances) we use Auto Scaling Groups and a Load Balancer

High Availability usually goes hand in hand with horizontal scaling
High Availability means running application / infrastructure in at least 2 Availability Zones
Goal of High Availability is to survive a data center loss / disaster


1. What is Cloud Computing	2. IAM	3. Budget
4. EC2	5. Security Groups	6. Storage
7. AMI	8. Scalability & High Availability	9. Elastic Load Balancing
10. Auto Scaling Group	11. S3	12. Databases
13. Other Compute Services	14. Deployments	15. AWS Global Infrastructure
16. Cloud Integrations	17. Cloud Monitoring	18. VPC
19. Security and Compliance	20. Machine Learning	21. Account Management and Billing
22. Advanced Identity	23. Other Services	24. AWS Architecting & Ecosystem
	25. Preparing for AWS Practitioner exam

Disclaimer: Content for educational purposes only, no rights reserved.

Most of the content in this series is coming from Stephane Maarek’s Ultimate AWS Certified Cloud Practitioner CLF-C02 2025 course on Udemy.

I highly encourage you to take the Stephane’s courses as they are awesome and really help understanding the subject.

More about Stephane Maarek:

This article is just a summary and has been published to help me learning and passing the practitioner exam.