This trace follows the actual state transitions behind the companion Infrastructure Changes Need Reviewable State. Each step below names its concrete inputs; values illustrate the mechanism and vary across implementations.
Step 1: Declare resource configuration
Infrastructure as code describes resources and their relationships in versioned files. A planning step compares the declared target with provider state and proposes changes. This makes infrastructure reviewable alongside application changes, but the plan is only as trustworthy as its inputs and state handling.
Step 2: Compare configuration with state
A change that adds a database replica can be reviewed for cost, networking, and failover consequences before apply. State records resource identities so the tool can update existing resources rather than create duplicates. Remote state storage and locking help teams coordinate concurrent changes.
Step 3: Review proposed changes
The plan shows intended provider changes against stored resource identity; review replacements, access changes, and secrets before applying.
Checkpoint: The plan shows intended provider changes against stored resource identity; review replacements, access changes, and secrets before applying. Confirm this state before advancing to Apply the plan.
Step 4: Apply the plan
Drift occurs when real infrastructure changes outside the declared workflow or provider state becomes stale. Applying a broad plan can replace resources or expose secrets if review misses destructive effects. Secrets should not be committed in plain text, and state files often contain sensitive values.
Step 5: Detect and reconcile drift
A plan proposes replacing a production database after a naming change. What should reviewers check before applying it, and how can resource identity be preserved?
The trace is done when this check holds: A plan proposes replacing a production database after a naming change. Compare the outcome against the companion article before making a performance claim.
Hardware, runtime, and observability notes
When tracing Trace: Infrastructure Changes Need Reviewable State in a live production environment (subsystem: distributed-systems, primary layer: system), keep the following step-level cost model and diagnostic checklist in mind:
- Step 1 (system): Declare resource configuration — verifies state invariants before advancing the execution pointer.
- Step 2 (system): Compare configuration with state — verifies state invariants before advancing the execution pointer.
- Step 3 (system): Review proposed changes — verifies state invariants before advancing the execution pointer.
- Step 4 (system): Apply the plan — verifies state invariants before advancing the execution pointer.
- Step 5 (system): Detect and reconcile drift — verifies state invariants before advancing the execution pointer.
Every transition across the system boundary carries both a direct CPU/memory cost (cache-line fills, descriptor lookups, lock acquisitions, or context switches) and a tail-latency queueing risk under contention. To verify this trace on your own service, capture latency histograms and hardware/kernel counters across each step boundary, compare cold-cache versus warm-cache execution paths, and confirm that error or timeout branches release all acquired descriptors, locks, and buffers cleanly.