Chapter 19: Growth Path (Kubernetes, HA, Multi-Node)

Word target: 3,200
Primary deliverable: Expansion decision framework
Key diagrams: Complexity trigger decision tree

Learning Goals

  • Decide when scaling complexity is justified.
  • Build migration strategy from single-node to distributed setups.
  • Keep architecture portable as hardware and providers change.

MVP Lab Worksheet

  • Objective: Define objective scale triggers.
  • Starting state: Stable baseline operations.
  • Steps:
    1. Set CPU/RAM/storage and incident-rate thresholds.
    2. Define migration trigger matrix.
    3. Publish ADR for next-stage architecture.
  • Evidence: Trigger matrix + ADR.
  • Exit criteria: Scale decisions become criteria-driven.
  • Rollback: Keep single-node baseline and defer migration.

Advanced Lab Worksheet

  • Objective: Run one small multi-node prototype.
  • Starting state: Trigger matrix approved.
  • Steps:
    1. Prototype clustered workload.
    2. Validate operational overhead and resilience gain.
    3. Compare gains against complexity cost.
  • Evidence: Prototype report with go/no-go outcome.
  • Exit criteria: Data-backed expansion decision.
  • Rollback: Decommission prototype and retain baseline.
Ubuntu Focus

Document Ubuntu-specific operational changes required when moving to clustered systems.