Immutable Infrastructure

Kind: approach

Layer: Resource Core

Record: architecture:immutable-infrastructure

Severity: contextual

Scope: infrastructure, deployment, reproducibility

Canonical: Ontology

An approach in which servers are replaced from a new image for every change, instead of being patched in place.

Listed in Architecture principles, after Configuration Externalization and before Single Responsibility Principle (SRP).

Requires

• Infrastructure as Code

Reinforces

• Environment Parity
• Reproducibility

Enables

• Deterministic Redeploys
• Instance Replacement over Mutation

Conflicts with

• In-Place Server Mutation

In tension with

• Deploy Time

Tensions

• Immutable Infrastructure / Deploy Time

Violated by

• In-Place Server Mutation

Severity

• contextual

Category

• Portability / Infrastructure / Deployment

Refactors

• Benchmarking

Linked from

• Correctness / Determinism / Verification
• Portability / Infrastructure / Deployment
• Scalability / Performance / Optimization
• Portability / Infrastructure / Deployment
• Severity levels
• The resolutions