It is very hard to build a robust distributed relational database system, because we need to do lots of tests to acquire the confidence that the user data is always safe, never lost or corrupted. In TiDB, we use the Chaos Engineering to ensure it. In this talk, I will talk about different types of fault injection we do in TiDB, show you how we build and evolve our own Chaos Platform - Schrodinger, and at last, share something else we have been doing like proof and automatic test.