About¶

Failover is an open-source Spring Boot library built at Société Générale to provide transparent failover for referential data.

Origins¶

The library was born from a recurring resilience problem across Société Générale's platforms: dozens of services share dependencies on the same small set of referential systems — currency tables, country lists, client profiles — that change slowly but are queried constantly.

A single referential outage cascades into a full-platform incident. Rather than solve this problem N times with bespoke try/catch logic, the team built a reusable, annotation-driven solution.

See ADR 1 for the founding decision.

Design Philosophy¶

• Minimal integration — one annotation on any Spring-proxied method. No framework coupling, no bespoke code per service.
• Business-driven expiry — TTL is a business decision. The framework enforces it; teams configure it.
• Observable by default — every store/recover event emits structured logs and Micrometer metrics. No extra instrumentation code required.
• Pluggable at every seam — store, key generation, expiry policy, payload enrichment, exception policy, context propagation — all replaceable without modifying the framework.

Maintainers¶

Acknowledgements¶

Failover was built at Société Générale to eliminate referential-outage cascades once — reusably — so every service benefits without repeating the same resilience logic.

License¶

Apache License 2.0 — see LICENSE.