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How do you migrate from Redis to Valkey with minimal downtime?
Databases & Caching · Intermediate level
Answer
For minimal downtime Redis to Valkey migration, I first classify whether the cache is disposable or authoritative. Pure caches can use warmup and endpoint cutover; authoritative data needs replication, backup/restore, dual-write, or a write freeze.
Technical explanation
Wire compatibility does not guarantee every feature, module, metric, or managed-service setting behaves identically.
If the workload is pure cache, cutover can tolerate misses; if Redis holds authoritative data, migration must be much stricter.
Validation should compare hit ratio, latency, evictions, memory, CPU, connection count, app errors, and failover behavior.
Hands-on example
Migration runbook:
1. Inventory Redis version, commands, clients, Lua scripts, modules, ACLs, cluster mode, and parameters.
2. Create equivalent Valkey cluster.
3. Restore backup or use online migration if supported.
4. Test staging app and replay synthetic traffic.
5. Lower TTLs and warm hot keys.
6. Switch endpoint/secret.
7. Monitor p95 latency, hit ratio, evictions, CPU, memory, and errors.
8. Keep old cluster for rollback window.
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