Redis › Redis Sentinel & High Availability
What is the difference between using Redis Sentinel and using Redis Cluster for achieving high availability, and how would you decide between them?
AdvancedAnswer
Sentinel is generally simpler to set up and manage, providing automatic failover for a primary and replica setup without sharding your data across multiple nodes, while Redis Cluster additionally provides horizontal scaling through sharding, making Cluster the better choice when your dataset needs to be distributed across multiple nodes for capacity reasons, while Sentinel remains a solid, simpler choice when a single node's capacity is sufficient and you mainly need automatic failover.
-- Sentinel: high availability without sharding
-- Cluster: high availability combined with shardingReal-world example A team whose entire dataset comfortably fits on a single Redis instance chooses Sentinel for its simplicity and automatic failover, while a much larger company whose data exceeds a single instance's capacity chooses Redis Cluster instead for both scaling and availability together.