The value in KV store are Opaque objects. 这里Opaque是指它对KV store来说是不透明的, 也就是说KV store不知道value存储的是什么, 它不会进行parse. 所有的parse都由application进行.

Reference

• Insider’s guide

Data Partition

Consistent hashing

• auto scaling
• heterogeneity 异质性, 多样性

the number of virtual nodes for a server is proportional to the server capacity. For example, servers with higher capacity are assigned with more virtual nodes. (this is called weight)

Data replication

replicate data to different servers on the ring.

• across DC replication. DCs are connected with high-speed networks.

Consistency

Consistency: Quorum Consensus

Inconsistency Detection: versioning

Vector Clock

Handling Failure

Failure Detection

Gossip Protocol