White Papers & Architectures

1. What this chapter covers

This is a short chapter that gathers the documents and tools AWS publishes as architectural yardsticks. They are not services you build systems with; they are the frame you use to evaluate the system you have just built.

• The Well-Architected Framework whitepaper
• The Well-Architected Tool
• AWS Trusted Advisor
• Reference architecture resources, for real-world work
• The Disaster Recovery on AWS whitepaper — see also the Disaster Recovery & Migrations chapter

2. Well-Architected Framework: the general guiding principles

Before the six pillars, the framework sets out a list of general guiding principles (https://aws.amazon.com/architecture/well-architected). They capture the spirit of cloud architecture and how sharply it departs from traditional infrastructure practice:

• Measure capacity instead of predicting it — the cloud lets you follow real demand rather than over-buying to feel safe.
• Rehearse at the size of production, because standing up an environment as large as production is something the cloud actually lets you do.
• Make architectural experiments cheap by automating them, so trying an idea out costs you very little.
• Let the architecture keep evolving rather than freezing one design and defending it.
• Take changing requirements as the input to the design, not as an inconvenience to it.
• Decide from data about how the system really behaves, not from intuition.
• Improve by running game days — deliberately exercising failure in order to learn from it.
• Simulate flash sale traffic, so peak load is rehearsed rather than discovered.

3. The six pillars

The Well-Architected Framework is built on six pillars:

#	Pillar
1	Operational Excellence
2	Security
3	Reliability
4	Performance Efficiency
5	Cost Optimization
6	Sustainability

The deck ends the list with a point worth holding on to: the pillars do not compete with one another, and they are not levers you set against each other — they work as a synergy. So resist framing a decision as “giving up security to buy cost optimization”; getting one pillar right generally pulls the others up with it.

Exam tip

Know all six pillars by their exact English names, and remember the deck’s closing point about them: they are a synergy, not a set of trade-offs to balance against each other.

4. AWS Well-Architected Tool

The AWS Well-Architected Tool is a free tool used to review your architectures against the six pillars of the Well-Architected Framework and to adopt architectural best practices.

It works in three steps:

1. Select your workload and answer the questions the tool puts to you.
2. Review your answers against each of the six pillars.
3. Obtain advice: get videos and documentation, generate a report, and see the results on a dashboard.

The tool lives at https://console.aws.amazon.com/wellarchitected, and the deck links the announcement post at https://aws.amazon.com/blogs/aws/new-aws-well-architected-tool-review-workloads-against-best-practices/.

5. AWS Trusted Advisor

Trusted Advisor produces a high level assessment of your AWS account with nothing to install anywhere. It inspects the accounts you point it at and hands back recommendations sorted into six categories:

• Cost optimization — spend you could be cutting.
• Performance — resources sized or configured below what they could be.
• Security — weak settings and resources left exposed.
• Fault tolerance — places where a single failure takes you down.
• Service limits — quotas you are running close to.
• Operational Excellence — how well the account is being run.

Two details about access levels, and they are exactly the sort of thing that gets asked:

• The full set of checks requires the Business & Enterprise Support plan.
• Programmatic access is available using the AWS Support API.

Exam tip

Do not mix the two tools up. The Well-Architected Tool is you answering questions about a workload so it can be reviewed against the six pillars. Trusted Advisor is AWS scanning your account and recommending across six categories — including Service limits, a category only Trusted Advisor has.

6. More architecture examples

By now the course has taken you through the architectural patterns that matter most, in two families:

• The Classic one, assembled from EC2, ELB, RDS, ElastiCache and the like.
• The Serverless one, assembled from S3, Lambda, DynamoDB, CloudFront, API Gateway and the like.

If you want to see more AWS architectures, the deck points at two official AWS pages: https://aws.amazon.com/architecture/ and https://aws.amazon.com/solutions/.

Quick recap

Item	What to remember for the exam
Well-Architected Framework	Six pillars: Operational Excellence, Security, Reliability, Performance Efficiency, Cost Optimization, Sustainability — a synergy, not trade-offs
Guiding principles	Stop guessing capacity, test at production scale, automate experimentation, allow evolutionary architectures, design based on changing requirements, drive architectures using data, improve through game days, simulate flash sale days
Well-Architected Tool	Free; pick a workload, answer questions, review against the six pillars, get a report and a dashboard
Trusted Advisor	Nothing to install; scans the account and recommends across six categories including Service limits; full set of checks needs Business & Enterprise Support; programmatic access via the AWS Support API
Reference architectures	Two broad families — Classic (EC2/ELB/RDS/ElastiCache) and Serverless (S3/Lambda/DynamoDB/CloudFront/API Gateway)