Raft layer on top of RocksDB ○ What is Raft? ● Written in Rust! TiKV API (gRPC) Transaction MVCC Raft (gRPC) RocksDB Raw KV API (https://github.com/pingc ap/tidb/blob/master/cmd /benchraw/main Data is organized by Regions ● Region: a set of continuous key-value pairs RPC (gRPC) Transaction MVCC Raft RocksDB ··· Raft ● 复制/分裂/负载均衡 Region 1:[a-e] split Region 1.1:[a-c] Region 1.2:[d-e]

Highly layered TiKV Key Space [ start_key, end_key) (-∞, +∞) Sorted Map RPC (gRPC) Transaction MVCC Raft RocksDB Node B Node C Node A Raft Raft Raft 256MB PD - Overview TiKV TiKV TiKV TiKV