How Facebook got consistency with MySQL

Facebook's MySQL deployment is somewhat unique with it's logtailers that use semi-synchronous replication to strike a balance between commit latency and data consistency.

This talk will explain how Facebook uses tried-and-tested asynchronous replication in combination with data-less logtailers running semi-synchronous replication to build robust MySQL replicasets.

We'll cover:

• An overview of the different types of replication.
• Why semi-synchronous replication is at the perfect intersection of commit latency and data consistency.
• How Facebook deploys logtailers and uses this hidden MySQL feature in production.
• Various automation and tooling we've built to manage it.
• Numerous edge-cases that we've discovered through years of operating MySQL at scale.