Redis is a in-memory data structure store, used as a database, cache and message broker. Onegini uses Redis for cache replication for multiple applications.
For our IDP we use Redis Sentinel. Redis Sentinel provides high availability for Redis. It is based on three boxes, each box running both a Redis process and a Sentinel process.
Configuration: quorum = 2 If the master M1 fails, S2 and S3 will agree about the failure and will be able to authorize a failover, making clients able to continue.