# Introduction
Bitalos, produced by Zuoyebang platform technical team, is a high-performance distributed storage system, core engine based on bitalosdb (self-developed high-performance KV storage engine), compatible with Redis protocol. As an alternative to Redis, it stores data with low-cost hard disk instead of expensive memory, takes full advantage of multi-core and provides excellent single-core performance, which can significantly reduce service costs.
Bitalos contains three main projects: dashboard (visual management platform), stored (storage service), and proxy (proxy service). Current open-source version is stable, and provides a complete industrial grade solution.
# Creator
Author: Xu Ruibo, joined Zuoyebang in Dec 2018 (working till now), is responsible for live class middle platform and user product middle platform, and leads the storage technology team to develop Bitalos from 0 to 1.
Contributors:Xing Fu, Lu Wenwei, Liu Fang, Li Jingchen
# Practice (Zuoyebang)
Number of clusters: 100+
Deploy: 3 clouds (Tencent, Ali, Baidu)
Application: carry 90% of the KV storage traffic in Zuoyebang
Peak traffic: QPS(20 Million),Network(5000Gbps)
Storage data: 200TB
Average reading time: 0.1ms, average writing time: 0.15ms
Availability: 99.999%
Stability: Since V1.0 was released in 2019, there have been zero online incidents
# Key Technology
Compatible with Redis protocol, low integration cost. Supports most commands, including LUA, distributed transactions.
High-performance data consistency architecture, based on bitalos-raft, deeply optimized Raft protocol, significantly improved write performance, and more stable election strategy and data synchronization process.
High-performance storage structure. By compressing redis composite data structure, greatly reduce disk I/O bytes, and improve system throughput.
Efficient horizontal scaling, supporting up to 1024 shards. Each shard includes at least 1 slot. Each slot can be migrated between any shards without affecting upstream services.
Multi-cloud disaster recovery, supports multi-room or multi-cloud deployment & management, and has a comprehensive complete downgrade & disaster recovery solution.
Multi-master write (enterprise edition support). Based on CRDT, optimize data synchronization and consistency strategy, ensure that conflicts can be adaptively resolved when written to multi-master in same shard, and guarantee eventual consistency.
High-performance core, equipped with self-developed KV engine: bitalosdb, which has a significant performance breakthrough compared to rocksdb.
Bithash (KV separation technology)
Bitalostree (high-performance compression index technology)
Bitalostable (cold and hot data separation technology)
# Technology accumulation(bitalosearch)
High performance distributed search & analysis engine, SQL protocol, focusing on AP scenarios, and has certain TP capabilities. It is being practiced internally, and the open source plan is to be determined
Compared to elasticsearch, bitalosearch has significant cost advantages. Hard disk consumption is saved 30%; data writing performance is improved by 25%; for complex analysis logic, query performance is improved by 20% to 500%