All 7 Clustering questions
More in Clustering
What is Redis Cluster, and what problem does it solve compared to running a single Redis instance? What is the difference between a master node and a replica node within a Redis Cluster? How does Redis Cluster automatically handle failover when a master node becomes unavailable? How do you monitor the overall health and status of a Redis Cluster to catch problems before they affect your application? How would you design a Redis Cluster deployment to properly balance high availability, performance, and cost for a large scale production application? What is a split brain scenario in the context of Redis Cluster, and how does the cluster protect against it?
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Redis › Clustering

What are the key limitations of Redis Cluster that developers should be aware of compared to a single instance Redis setup?

Intermediate

Answer

Redis Cluster does not support multi key operations across keys that live on different nodes unless you use hash tags to force them onto the same slot, has limited support for selecting a specific numbered database since cluster mode only supports database zero, and requires cluster aware client libraries to properly route commands to the correct node.
-- This fails in cluster mode unless both keys share a hash tag
redis-cli mset key1 'a' key2 'b' -- error if on different nodes
Real-world example A team migrating from a single Redis instance to a cluster discovers several multi key operations in their code need to be redesigned using hash tags, since those keys were not guaranteed to live on the same node anymore.

Common follow-ups: How do you identify multi key operations in existing code before migrating to a cluster?;Why does Redis Cluster only support database zero?

Cluster Sharding & Hash Slots;Connection Pooling & Client Libraries
All 7 Clustering questions