Tencent Financial Technology's Distributed MySQL Architecture for Financial-Grade Services

Tencent Financial Technology (FiT) operates the world’s largest financial‑grade distributed MySQL cluster, supporting WeChat Pay, QQ Wallet, and other services, and has achieved 99.999% database availability, handling over 200,000 TPS during peak events.

Financial applications demand strict data consistency and reliability, leading FiT to choose open‑source MySQL over Oracle or NoSQL solutions because of its ACID support, MVCC concurrency, and flexible replication topology.

FiT’s architecture shards data across thousands of MySQL instances, storing core user‑fund data in multiple shards and using lossless semi‑synchronous replication to ensure financial‑grade durability.

The system adopts a multi‑active N‑center design: each shard has a primary node in every data‑center, with real‑time replication to two other centers. Raft consensus selects a new primary on failure, and automatic cross‑center switching keeps services available without manual intervention.

Database optimization includes four real‑time synchronized replicas per shard across three data‑centers, with a priority‑based failover algorithm that prefers same‑site replicas to minimize latency, and a name‑service/DNS layer that provides transparent read/write routing.

Data safety is reinforced by minute‑level logical consistency checks, business‑level transaction verification, and the Medusa backup system that performs full and incremental backups with automated validation and restore testing.

In practice, FiT’s cluster now runs nearly ten thousand MySQL instances managed by the FMHA platform, supporting continuous 99.999% availability, RPO 0 and RTO 30 seconds, and successful disaster‑recovery drills across data‑centers.

Looking ahead, FiT is exploring MySQL Group Replication (MGR) with Paxos‑based consensus and multi‑master capabilities to further evolve its financial‑grade database architecture.