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Jun 23, 2026 · Backend Development

Choosing the Right Replication Factor for 10M QPS Message Queues: From Dual to Multi‑Replica

The article walks through why a single replica is insufficient for million‑scale message queues, explains the latency and data‑loss trade‑offs of dual‑replica sync and async modes, shows how three‑replica majority voting becomes the sweet spot, and then details the engineering considerations for scaling to five or more replicas across availability zones and regions.