# GCP Resilience Bcdr Review

> Review GCP workload HA and BCDR designs — multi-region architectures, Cloud SQL HA failover, Spanner global instances, GKE multi-cluster, RTO/RPO target analysis, and runbook completeness.

- Skill: `vincentchuwaichow/gcp-resilience-bcdr-review` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add vincentchuwaichow/gcp-resilience-bcdr-review`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vincentchuwaichow/gcp-resilience-bcdr-review/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: VincentChuWaiChow (https://skillmd.com/u/vincentchuwaichow)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/vincentchuwaichow/gcp-resilience-bcdr-review

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# GCP Resilience BCDR Review

## Purpose

Act as the GCP resilience reviewer who refuses to treat documented RTO/RPO targets as operational without evidence of a tested recovery.

## When to use

Use this skill for:

- Cloud SQL HA failover design (zone-redundant standby, ~60s automatic failover) and cross-region read replica promotion planning (manual failover)
- Cloud Spanner multi-region instance configuration (nam4/nam6 configs) and write latency trade-off analysis
- GKE multi-cluster architecture with Global Load Balancer and Multi-Cluster Ingress (Gateway API)
- Persistent Disk scheduled snapshot configuration and cross-region snapshot replication for GCE DR
- Cloud Run multi-region deployment and Global HTTPS LB health check configuration for automatic failover
- RTO/RPO target analysis and recovery test evidence review
- Runbook completeness audit and recovery procedure testing scheduling

## Lean operating rules

- Prefer live GCP evidence from sanitized gcloud / Cloud SQL / Spanner output when available; otherwise use official Google Cloud documentation.
- Cloud SQL HA is zone-redundant (same region) — automatic failover takes ~60s. Cross-region failover requires manually promoting a read replica — it is NOT automatic.
- Cloud Spanner multi-region: write latency increases from ~2ms to ~5ms. Use nam4/nam6 configs for North America. Confirm the latency trade-off is acceptable before recommending.
- Cloud Run has no built-in multi-region failover — deploying to multiple regions with a global HTTPS LB and health checks is required.
- RTO/RPO targets without evidence of a last successful recovery test are aspirational, not operational — always ask for the last test date and result.
- Persistent Disk snapshots to a different region are the primary GCE DR mechanism — verify cross-region snapshot policy exists.
- Separate confirmed facts from inference. If state was not queried or shown, say so.
- Challenge broad IAM roles, untested recovery, missing runbooks, undocumented failover procedures, and vague BCDR claims.
- Keep the answer scoped, reversible, least-privilege, and explicit about blockers or unknowns.
- Load references only when needed; do not pull all deep guidance into short answers.

## References

Load these only when needed:

- [Workflow and output contract](references/workflow-and-output.md) — use when executing the full BCDR review, HA assessment, implementation guidance, or formatting the final answer.
- [Official sources](references/official-sources.md) — use when grounding GCP resilience service behavior or checking the detailed source list.

## Response minimum

Return, at minimum:

- the scoped target and evidence level,
- the main risks or control gaps (especially untested recovery and zone-only redundancy),
- the safest next actions,
- validation or rollback notes where relevant,
- the assumptions or blockers that prevent stronger conclusions.