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Before flipping traffic, you should have a communications playbook and a rollback plan ready if you intend to shift workloads to Amazon Neptune (graph DB) and are concerned about performance regressions. When query patterns or index utilization don't correspond with production traffic, graph database migrations can quickly become chaotic.
Rollback Plan

• Blue/Green or Shadow Traffic: Don’t cut over 100% on day one. Run Neptune in parallel with your legacy DB, replaying queries (shadow mode) until metrics line up. This makes rollback as simple as stopping the switch.
• Feature Flags at Query Layer: Wrap Neptune calls behind a service flag. If p95 query latency spikes or error rates jump, toggle back to the old DB without redeploys.
• Rollback Triggers: Define red lines up front:
• Latency >2x baseline for >15 min
• Error rate >3–5% sustained
• Query timeout ratio above threshold
• If those breach → rollback, no debate.
• Data Sync Strategy: If Neptune is being used as a secondary, keep continuous CDC (change data capture) from primary. That way rollback doesn’t cause data drift.

Comms Plan

• Internal:
• War room channel with Eng, SRE, Product.
• Shared dashboards (CloudWatch + custom query telemetry).
• Pre-assign who makes the rollback call (don’t decide in chaos).
• External (customers/users):
• If rollback is fast, you may not need to say anything.
• If users saw errors/timeouts, update status page: Some requests failed due to database latency. We rolled back and systems are stable.
• Have support macros pre-drafted so customers get consistent answers (issue resolved, no data loss, no action needed on your side).
• Stakeholders: Exec/biz teams get a short alert: Neptune rollout paused due to perf regressions. Legacy infra restored. ETA for reattempt after RCA.

When enabling new Amazon Neptune features, you should avoid any change-freeze windows during your application's peak business hours. While Amazon performs its own maintenance, using a robust deployment strategy is more critical for ensuring stability. You should also avoid periods of high-volume data ingestion, like bulk load operations, which could interfere with replication.

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