The Reliability pillar focuses on ensuring a workload performs its intended function correctly and consistently when it’s expected to. This includes the ability to operate and test the workload through its total life-cycle. Key topics include distributed system design, recovery planning, and how to handle change.

There are five design principles for Reliability in the cloud:

• Automatically recover from failure
• Test recovery procedures
• Scale horizontally to increase aggregate workload availability
• Stop guessing capacity
• Manage change in automation