wish helps you Sharding is almost replication's antithesis, though they are orthogonal concepts and work well together. Sharding, also known as partitioning, is splitting the data up by key; While replication, also known as mirroring, is to copy all data.
may help you . Redis only supports replication of whole instances. Limiting replication to a key prefix or database is not possible. Running two instances of Redis is simplest and reliable option. Another way would be to write a custom replication program which is difficult and failure prone in comparison.
Difference between Redis Replication and Redis Sentinel
I think the issue was by ths following , You use them both together. If you have a master and a couple of slaves, replication makes sure that data between all three remains consistent, but sentinel will handle promoting a slave to a master if the master dies, redirecting new requests to the new master, and notifying someone about what has happened.