Kiwi

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Introduction

Kiwi is a Redis-compatible key-value database built in Rust, providing high capacity and strong consistency through RocksDB and the Raft protocol.

Features

• Dual Runtime Architecture: Network and storage runtimes are separated for performance isolation
• RocksDB Backend: Uses RocksDB as the persistent storage backend
• Redis Protocol Compatibility: Highly compatible with Redis protocol
• Raft Consensus: Integrates OpenRaft for strong consistency and high availability
• Adaptor Pattern: Custom adapter layer bridging storage with OpenRaft
• High Performance: Optimized request processing with dedicated thread pools
• Asynchronous Communication: Message channel-based asynchronous communication
• Fault Isolation: Network and storage operations run in isolated runtimes

Architecture

src/server/    → Entry point (main.rs)
src/net/       → TCP server, connection handling, cluster routing
src/cmd/       → Command definitions: Cmd trait, CmdMeta, command table
src/executor/  → Command executor: tokio async task pool
src/storage/   → Multi-instance RocksDB, column families, TTL
src/engine/    → Engine trait abstraction over RocksDB
src/resp/      → RESP protocol: parser, encoder, RespData types
src/raft/      → Raft consensus: OpenRaft integration, state machine, router
src/conf/      → Configuration: loading, validation, RaftClusterConfig
src/client/    → Client context: connection state, argv, reply buffer
src/common/runtime/ → Runtime management: async channel between net & storage
src/common/macro/   → Proc macros: #[stack_trace_debug]
src/kstd/      → Utilities: LockMgr (sharded key-level locking)

Request Flow

Client → TCP accept [network runtime] → RESP parse → Command lookup
  → CmdExecutor [network runtime] → Cmd.execute() calls StorageClient
    → MessageChannel →
  → StorageServer [storage runtime] → RocksDB
    ← oneshot response ←
  → RESP encode [network runtime] → write back to client

Roadmap

• ✅ Dual-runtime architecture for performance isolation
• ✅ Message channel-based async communication
• ✅ Basic Redis commands (GET, SET, DEL, etc.)
• ✅ OpenRaft integration via adaptor pattern
• 🚧 Most Redis commands
• 🚧 Complete cluster mode
• 🚧 Extended command support and execution optimization
• 🚧 Module extension capabilities
• 🚧 Comprehensive metrics and monitoring

Getting Started

Prerequisites

# Rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# protobuf compiler (macOS)
brew install protobuf

# protobuf compiler (Linux)
apt install protobuf-compiler

Get the Code

git clone https://github.com/arana-db/kiwi.git
cd kiwi

Standalone Mode

make standalone                    # builds (release) and starts kiwi on 127.0.0.1:7379

# In another terminal:
redis-cli -p 7379 set foo bar     # OK
redis-cli -p 7379 get foo         # "bar"

Cluster Mode

make cluster                       # start a 3-node Raft cluster (default)
make cluster NODES=5               # start a 5-node cluster

See docs/cluster.md for the manual step-by-step procedure and Raft architecture details.

Documentation

Dependencies

RocksDB (Temporary Fork)

This project uses a customized fork of rust-rocksdb because the official crate does not yet support the TablePropertiesCollector FFI functions required by the Raft module. Once the needed functionality lands in upstream rust-rocksdb, we will switch back.

Contributing

Contributions are welcome. See CONTRIBUTING.md for guidelines.

License

Apache License 2.0. See LICENSE.