# alibaba/cobar

a proxy for sharding databases and tables

Repository: https://github.com/alibaba/cobar
Canonical: https://ross.abutalabs.com/products/cobar
Language: Java
License: Apache-2.0
License Family: permissive
Last push: 2023-08-07T02:08:43+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4613, "days_push": 1123, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3187, forks 1202 (observed 2026-08-28T04:07:48.067836+00:00)

## What it is
Cobar is a database proxy from Alibaba that shards MySQL databases and tables, speaking the MySQL protocol so applications can use it as a drop-in MySQL replacement. It supports adding MySQL instances as the business grows and provides high availability through clustering of both the proxy and underlying MySQL nodes.

## Use cases
- shard a large MySQL database across multiple instances
- scale MySQL horizontally as data grows
- split large tables across MySQL servers transparently
- add a proxy layer in front of MySQL without changing application code
- achieve high availability for MySQL-backed services

## When to choose
- your application uses MySQL and you need transparent horizontal sharding
- you want to scale MySQL without modifying client code
- you need a battle-tested proxy layer compatible with the MySQL protocol

## When to avoid
- you use databases other than MySQL as the underlying storage
- you need advanced SQL features or complex cross-shard transactions
- you want an actively developed project with modern community support

## Facets
- artifact type: service
- maturity: maintenance
- function: database, proxy, routing, http-server
- domain: databases, backend, microservices
- platform: jvm, self-hosted
- tags: database-sharding, mysql-proxy, middleware, horizontal-scaling, high-availability, linux

## Member repositories
- alibaba/cobar (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:48.067836+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:24:58.908738+00:00, confidence not recorded.
  - readme: https://github.com/alibaba/cobar (fetched 2026-08-28T04:07:48.067836+00:00, sha d9e2a360af61)
- Data as of 2026-08-30T08:39:29.467469+00:00.