Implementing the Core Services of Spring Authorization Server with Redis

Spring Authorization Server's default in-memory storage becomes problematic for production applications due to lack of persistence and horizontal scaling support. This guide demonstrates implementing Redis-based persistence for core authorization services including registered clients, tokens, authorization states, and consents. The implementation involves creating entity models, Spring Data repositories, custom service implementations, and Redis configuration. Key components include OAuth2RegisteredClient entities, authorization grant entities for different OAuth2 flows, and corresponding repositories and services that handle persistence operations. The tutorial uses an embedded Redis server and provides a complete working example with authentication flow demonstration.