AWS Well-Architected Framework & Cloud Migration
The AWS Well-Architected Framework organizes best practices into 6 pillars for building robust cloud infrastructure. The AWS Cloud Adoption Framework (CAF) helps organizations plan migration across 6 perspectives, while the 7 Rs strategies guide decisions about what to do with each existing workload.
1. AWS Well-Architected Framework Overview
The AWS Well-Architected Framework helps cloud architects build secure, high-performing, resilient, and efficient infrastructure. It is organized into 6 pillars, each with design principles and best practices evaluated through the AWS Well-Architected Tool — a free guided review service in the console.
2. The Six Pillars
| Pillar | Core Question | Key Practices |
|---|---|---|
| Operational Excellence | How do you run and improve operations? | Infrastructure as code; small reversible changes; anticipate failure |
| Security | How do you protect your workloads? | Least privilege; enable traceability; encrypt data; automate security |
| Reliability | How do you recover from failures? | Test recovery procedures; auto-recover; scale horizontally |
| Performance Efficiency | How do you use resources efficiently? | Use managed/serverless services; go global in minutes; experiment often |
| Cost Optimization | How do you avoid unnecessary costs? | Right-size resources; use correct pricing model; implement cloud financial management |
| Sustainability | How do you minimize environmental impact? | Maximize utilization; use efficient hardware; reduce idle resources |
3. AWS Well-Architected Tool
- Free service available in the AWS Management Console
- Asks guided questions about your workload against each pillar
- Produces a risk report identifying high-risk issues (HRIs) and medium-risk issues (MRIs)
- Provides specific improvement recommendations with links to best practices
- Should be used regularly as architecture evolves
Tip for the exam: The Well-Architected Tool is for architectural review. AWS Config is for compliance monitoring. Trusted Advisor checks existing resource configurations.
4. AWS Cloud Adoption Framework (AWS CAF)
The AWS CAF helps organizations understand what capabilities they need to build or improve before and during migration. It organizes guidance into 6 perspectives:
| Perspective | Focus | Who Owns It |
|---|---|---|
| Business | Ensuring cloud investments deliver business value | CFO, CEO, Business stakeholders |
| People | Culture change, training, org readiness | CHRO, HR |
| Governance | Minimizing risk and maximizing value | CIO, Program managers |
| Platform | Building scalable cloud platforms | CTO, Architects |
| Security | Ensuring data and systems are protected | CISO, Security team |
| Operations | Defining how cloud services are operated | IT Operations |
AWS CAF Benefits: Reduced business risk · Improved ESG performance · Increased revenue · Improved operational efficiency
5. Migration Strategies — The 7 Rs
When deciding what to do with each existing workload during migration to AWS:
| Strategy | Description | Effort | Cloud Benefit |
|---|---|---|---|
| Rehost | Lift-and-shift to EC2; no code changes | Lowest | Low |
| Replatform | Minor optimizations (e.g., move to managed RDS) | Low-Medium | Medium |
| Re-architect | Redesign as cloud-native (microservices, serverless) | Highest | Highest |
| Repurchase | Replace with SaaS product | Medium | Medium |
| Retain | Keep on-premises; not ready | None | None |
| Retire | Decommission unused apps | Lowest | Immediate cost savings |
| Relocate | VMware Cloud on AWS; no changes needed | Low | Low-Medium |
6. AWS Snow Family — Physical Data Transfer
When network transfer would take weeks or months (e.g., 100 TB over 1 Gbps line = ~9 days minimum, often longer in practice), AWS ships physical devices:
| Device | Capacity | Form Factor | Use Case |
|---|---|---|---|
| Snowcone | 8 TB HDD / 14 TB SSD | Backpack-portable | Remote/edge locations; small migrations |
| Snowball Edge Storage | 80 TB usable | Rugged briefcase appliance | Large data migrations |
| Snowball Edge Compute | 40 TB + GPU or EC2 | Rugged appliance | Edge ML; local processing before shipping |
| Snowmobile | 100 PB | 45-foot shipping container truck | Entire datacenter migration |
General rule: If transferring data over your existing network would take more than a few weeks → use Snow Family.
7. Other Migration Services
| Service | Purpose |
|---|---|
| AWS Migration Hub | Central tracking dashboard for all migration activities |
| AWS Application Migration Service | Lift-and-shift server replication to AWS |
| AWS DMS (Database Migration Service) | Migrate databases with minimal downtime |
| AWS Schema Conversion Tool (SCT) | Convert database schema when changing engines |
8. CLF-C02 Quick Reference
| Topic | Key Fact |
|---|---|
| Well-Architected pillars (6) | Operational Excellence, Security, Reliability, Performance Efficiency, Cost Optimization, Sustainability |
| Well-Architected Tool | Free; guided questionnaire; produces high/medium risk report |
| CAF perspectives (6) | Business, People, Governance, Platform, Security, Operations |
| Rehost | Lift-and-shift; no code changes; fastest migration |
| Replatform | Minor optimizations; e.g. MySQL on EC2 to RDS |
| Re-architect | Full cloud-native redesign; highest effort and benefit |
| Repurchase | Replace with SaaS |
| Retire | Decommission unused applications |
| Retain | Keep on-premises; not ready to migrate |
| Relocate | VMware Cloud on AWS |
| Snowcone | 8 TB; portable; edge locations |
| Snowball Edge | 80 TB; large data migrations |
| Snowmobile | 100 PB; entire datacenter migration via truck |
Practice Questions7
Q1. How many pillars make up the AWS Well-Architected Framework?
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Q2. A company wants to ensure their AWS workload can automatically recover from failures, scale to meet demand, and meet recovery time objectives. Which Well-Architected pillar should guide their design?
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Q3. Which AWS Well-Architected pillar focuses on minimizing the environmental impact of running cloud workloads by using resources efficiently?
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Q4. A company is planning to migrate to AWS and wants to develop a structured plan that identifies gaps in their organization's skills, processes, and technology. Which AWS framework is designed for this purpose?
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Q5. A company wants to migrate their on-premises web application to AWS as quickly as possible with minimal code changes. They plan to simply move the existing servers to AWS virtual machines. Which migration strategy does this describe?
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Q6. A company audited its application portfolio before cloud migration and found several legacy applications that are no longer used by anyone in the organization. What is the recommended migration strategy for these applications?
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Q7. Which AWS service provides a free, self-service tool to review your AWS workloads against the AWS Well-Architected Framework pillars and identify improvement opportunities?
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