Exam Readiness: AWS Certified Solutions Architect – Associate

The Exam Overview

Module 1 - Design Resilient Architectures

RPO and RTO

• RPO Is Recovery Point Objective. How much data is lost if a system fails?
• RTO Is Recovery Time Objective. How long does it take for the system to recover and come back on-line again?

Text Axioms 1

• Expect "Single-AZ" will never be a right answer
• Using AWS managed services should always be prefered
• Fault-tolerant and high availability are not the same thing
  • Fault tolerant: Means that the system hides the failure from the users and there is no loss of service
  • High availability: Means that the system will always be up and it can fail-over in the event of failure
• Expect that everything will fail at some point and design accordingly

Module 2 - Design Performant Architectures

Security:

• AWS Shield: WS Shield is a managed Distributed Denial of Service (DDoS) protection service
• AWS WAF: AWS WAF is a web application firewall that helps protect your web applications from common web exploits that could affect application availability, compromise security, or consume excessive resources

Text Axioms 2

• If data is unstructured, Amazon S3 is generally the storage solution.
• Use caching strategically to improve performance.
• Know when and why to use Auto Scaling.
• Choose the instance and database type that makes the most sense for your workload and performance need.

Module 3 - Specify Secure Applications and Architectures

Text Axioms 3

• Look down the root user
• Security groups only allow. Network ACLs allow explicitly deny.
• Prefer IAM roles over access keys

Module 4 - Design Cost-Optimized Architectures

Text Axioms 4

• If you know it's going to be on, reserve it.
• Any unused CPU time, is a waste of money.
• Use the most cost-effective data storage service and class.
• Determine the most cost-effective EC2 pricing model and instance type for each workload.

Module 5 - Define Operationally-excellent Architectures

Text Axioms 5

• IAM Roles are easier and safer than keys and passwords.
• Monitor metrics across the system.
• Automate responses to metrics where appropriate
• Provide alerts for anomalous conditions