Introduction
The AWS Well-Architected Framework is a set of guidance from AWS that describes how to design and operate sound workloads in the cloud. A workload is a set of resources and code that together deliver a business value, for example an application and its supporting services. This guide explains what the framework is, why it exists, its six pillars, and how a review is carried out.
What is it?
The framework organizes its guidance into six areas that are called pillars, each covering a distinct concern. It also provides a set of questions against which a workload can be measured, so that risks can be identified and improvements can be planned. The framework is guidance rather than a service, although AWS provides a tool that supports its use.
Why does it exist?
Many architectural problems recur across different systems, such as a lack of resilience, weak security, or unnecessary cost. The framework exists to capture the lessons that AWS has learned from many workloads and to present them as a consistent set of principles. By measuring a workload against these principles, teams can find weaknesses before they cause problems.
How it works
A workload is measured against the questions of each pillar, an exercise that is called a Well-Architected review. The review identifies risks and produces a list of improvements, which are then prioritized and addressed. The AWS Well-Architected Tool, a service that guides a review and records its results, can be used to carry out and track the process. Reviews are repeated over time, because a workload changes.
The six pillars
Each pillar covers a distinct concern. Operational excellence concerns running and improving workloads. Security concerns protecting data and systems. Reliability concerns recovering from failure and meeting demand. Performance efficiency concerns using computing resources well. Cost optimization concerns avoiding unnecessary spending. Sustainability concerns reducing the environmental impact of a workload.
Advantages
- Consistency. Workloads are measured against a common set of principles.
- Early detection. Risks are found before they cause problems.
- Shared vocabulary. Teams describe architecture using the same terms.
- Broad coverage. The six pillars address operations, security, reliability, performance, cost, and sustainability together.
Disadvantages
- Effort. A thorough review takes time and involvement from the team.
- Guidance, not automation. The framework identifies improvements but does not make them.
- Judgement required. The principles must be applied with an understanding of the specific workload.
Common use cases
- Reviewing a new workload before it goes live.
- Assessing an existing workload for risks and improvements.
- Guiding design decisions with a shared set of principles.
- Comparing options against the pillars when planning an architecture.
Best practices
- A review should be carried out at major milestones and repeated periodically as the workload changes.
- The identified risks should be prioritized and tracked to completion rather than only recorded.
- All six pillars should be considered, not only the ones that are most familiar.
- The principles should be applied with an understanding of the specific workload and its requirements.
Common mistakes
- A review is treated as a one-time exercise and is never repeated.
- Only the security or cost pillar is considered, and the others are ignored.
- The findings are recorded but never acted upon.
- The principles are applied rigidly without regard to the needs of the workload.
Related AWS services
- AWS Well-Architected Tool guides a review and records its results.
- AWS Trusted Advisor provides checks that support several of the pillars.
- Amazon CloudWatch provides the monitoring on which operational excellence depends.
Frequently Asked Questions
- What is the AWS Well-Architected Framework?
- A set of guidance from AWS that describes how to design and operate reliable, secure, efficient, and cost-effective workloads. It organizes this guidance into six pillars and provides questions that a workload can be measured against.
- What are the six pillars?
- Operational excellence, security, reliability, performance efficiency, cost optimization, and sustainability. Each covers a distinct area of concern, and together they describe a sound architecture.
- What is a Well-Architected review?
- An exercise in which a workload is measured against the questions of the framework. It identifies risks and produces a list of improvements, and it can be carried out with the AWS Well-Architected Tool.
- Is the framework only for large systems?
- No. It applies to workloads of any size. The pillars describe general principles that are useful for a small application as well as for a large system.
- How often should a review be done?
- At major milestones and repeated periodically, because a workload changes over time. Regular reviews keep the architecture aligned with the pillars as requirements evolve.
This article is the summary. The book is the full, continuously updated reference: the six pillars applied to real serverless architectures, with worked examples and reviews.
View the book