What is the main principle of immutable infrastructure?

What is the main principle of immutable infrastructure?

• A. Do not modify running components; replace them with new instances for changes
• B. Patch in place
• C. Always maintain two identical environments
• D. Use only virtual machines

Answer: (A)

Immutable infrastructure means you don’t modify a running component. When a change is needed, you build a new artifact (a new VM image or container), deploy it, switch over to the new instance, and retire the old one. This makes deployments predictable and repeatable because every change comes from a fresh, versioned image rather than patching something that’s already running. Rollbacks become simple too: you just revert to the previous image. It also reduces drift, since configuration is baked into the new image at provisioning time rather than applied piecemeal after deployment. In practice, automation and infrastructure-as-code workflows support this by producing replaceable, verifiable artifacts that can be recreated quickly. Patch in place contradicts the principle because it mutates live components and invites drift. Keeping two identical environments describes deployment strategies like blue-green, not the core idea of immutable components. Using only virtual machines isn’t a requirement; immutability applies to both VM-based and containerized setups.

Immutable infrastructure means you don’t modify a running component. When a change is needed, you build a new artifact (a new VM image or container), deploy it, switch over to the new instance, and retire the old one. This makes deployments predictable and repeatable because every change comes from a fresh, versioned image rather than patching something that’s already running. Rollbacks become simple too: you just revert to the previous image. It also reduces drift, since configuration is baked into the new image at provisioning time rather than applied piecemeal after deployment. In practice, automation and infrastructure-as-code workflows support this by producing replaceable, verifiable artifacts that can be recreated quickly.

Patch in place contradicts the principle because it mutates live components and invites drift. Keeping two identical environments describes deployment strategies like blue-green, not the core idea of immutable components. Using only virtual machines isn’t a requirement; immutability applies to both VM-based and containerized setups.