MySQL Replication Explained: Source-Replica Setup

Replication copies data changes from one MySQL server (source) to others (replicas) in near real-time. It powers read scaling, high availability — and gives analysts a server they can hammer without touching production.

Key Points

• The source writes changes to a binary log; replicas replay it
• Read scaling: send SELECT-heavy analytics to replicas
• Failover: promote a replica if the source dies
• Asynchronous by default; semi-synchronous adds a durability guarantee
• GTID-based replication simplifies failover and consistency tracking
• Best practice: run BI tools and heavy reports against a replica