Reliability Pillar

The Reliability pillar of the Azure Well-Architected Framework focuses on ensuring that your workload can withstand failures and recover quickly when they occur. Failures in the cloud are not a question of "if" but "when." A well-architected system anticipates failures and is designed to handle them gracefully.

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Design Principles

The Reliability pillar is built on several key design principles:

Design for Failure

Assume that every component in your system can and will fail. This includes hardware, software, network connections, and even entire Azure regions. When you design for failure, you build in redundancy, retries, and fallback mechanisms from the start rather than adding them as an afterthought.

Design for Self-Healing

A self-healing system detects failures and takes corrective action automatically, without human intervention. This might mean restarting a failed container, rerouting traffic away from an unhealthy region, or automatically provisioning a replacement resource.

Design for Scale-Out

Rather than relying on a single, powerful instance (scale-up), distribute your workload across multiple smaller instances (scale-out). This approach is inherently more resilient because the failure of a single instance has limited impact.

Observe and Measure