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I'm using redis cluster 3.0.1.
I think redis cluster use consistent hashing. The hash slots are similar to virtual nodes in consistent hashing. Cassandra's data distribution is almost the same as redis cluster, and this article said it's consistent hashing.
But the redis cluster turorial said redis cluster does not use consistent hash.
What do I miss? Thanks.
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As it is known, Redis uses the CRC16 algorithm to map keys to hash slots.
Each node in the cluster is responsible for a range of data based on the hash value. So there you go, that's consistent hashing and how it works in a distributed database like Apache Cassandra, the derived distributed database DataStax Enterprise, or the mostly defunct (RIP) Riak.
How It Works. Redis Cluster is an active-passive cluster implementation that consists of master and slave nodes. The cluster uses hash partitioning to split the key space into 16,384 key slots, with each master responsible for a subset of those slots.
The Redis Cluster supports only one database - indicated if you have a big dataset - and Redis supports multiple databases. The Redis Cluster client must support redirection, while the client used for Redis doesn't need it.
You are right, virtual nodes is quite simalar with hash slot.
But virtual nodes is not an original concept of consistent hashing, but more like a trick used by Cassandra based on consistent hashing. So it's also ok for redis to say not using consistent hashing.
So, don't bother with phraseology.
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