# Sentinel

A powerful flow control component enabling reliability, resilience and monitoring for microservices. (面向云原生微服务的高可用流控防护组件)

Repository: https://github.com/alibaba/Sentinel
Canonical: https://ross.abutalabs.com/products/sentinel
Homepage: https://sentinelguard.io/
Language: Java
License: Apache-2.0
License Family: permissive
Topics: alibaba, java, microservice, circuit-breaker, rate-limiting, reliability, cloud-native, microservices, resiliency
Last push: 2026-05-27T08:58:51+00:00
Link (homepage): https://sentinelguard.io/

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 84, release rhythm 52, longevity 100
- inputs: {"age_days": 3073, "days_push": 98, "days_rel": 104, "gap_med": 216, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 23142, forks 8139 (observed 2026-08-28T04:11:34.522058+00:00)

## What it is
Sentinel is a flow control and reliability library for microservices, providing rate limiting, traffic shaping, concurrency limiting, circuit breaking, and adaptive overload protection. It offers real-time monitoring, framework integrations (Spring Cloud, Dubbo, gRPC, Quarkus), and polyglot support for Java, Go, C++, and Rust.

## Use cases
- rate limit burst traffic to protect my microservice
- add circuit breaking for unreliable downstream services
- limit concurrent requests in a Java service
- monitor real-time traffic metrics of my services
- apply adaptive overload protection in a distributed system
- integrate flow control with Spring Cloud or Dubbo

## When to choose
- you need battle-tested flow control and circuit breaking for JVM or Go microservices
- you want out-of-the-box adapters for Spring Cloud, Dubbo, or gRPC
- you need real-time monitoring and cluster flow control in cloud-native systems

## When to avoid
- you need a standalone API gateway or edge proxy rather than an in-process library
- your stack uses languages without a Sentinel port
- you only need simple client-side HTTP retries without traffic governance

## Facets
- artifact type: library
- maturity: stable
- function: rate-limiting, monitoring, middleware, microservices, caching
- domain: microservices, cloud-computing, backend
- platform: jvm, go, cpp, rust, cloud
- tags: circuit-breaker, flow-control, traffic-shaping, resilience, overload-protection, cloud-native, spring-cloud, dubbo, grpc, devops, docker, kubernetes

## Member repositories
- alibaba/Sentinel (main) score 76
- alibaba/sentinel-golang (sdk) score 63

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:34.522058+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 2026-08-29T16:56:46.882105+00:00, confidence not recorded.
  - readme: https://github.com/alibaba/Sentinel (fetched 2026-08-28T04:11:34.522058+00:00, sha 960e6c925036)
  - homepage: https://sentinelguard.io/ (fetched 2026-08-29T07:54:38.910292+00:00, sha 44136fa355b3)
- Data as of 2026-08-30T08:39:29.467469+00:00.