# Netflix/Hystrix

Hystrix is a latency and fault tolerance library designed to isolate points of access to remote systems, services and 3rd party libraries, stop cascading failure and enable resilience in complex distributed systems where failure is inevitable.

Repository: https://github.com/Netflix/Hystrix
Canonical: https://ross.abutalabs.com/products/hystrix
Language: Java
License Family: other
Last push: 2025-12-17T03:21:02+00:00

## Health v2 (maintenance only)
Score: 48/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 57, release rhythm 8, longevity 100
- inputs: {"age_days": 5035, "days_push": 259, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 24474, forks 4678 (observed 2026-08-28T04:11:37.125671+00:00)

## What it is
Hystrix is a Java library for latency and fault tolerance in distributed systems, providing circuit breakers, thread/semaphore isolation, fallbacks, and request collapsing to stop cascading failures. It is now officially in maintenance mode, with Netflix recommending resilience4j for new projects.

## Use cases
- stop cascading failures between microservices
- add circuit breakers around remote service calls
- implement fallbacks and graceful degradation
- isolate third-party library calls with bulkheads
- monitor real-time dependency health with dashboards
- add timeouts and fail-fast behavior to remote calls

## When to choose
- maintaining an existing JVM application already built on Hystrix
- you need battle-tested circuit breaker semantics on Java 6+
- you rely on its mature dashboard and monitoring integrations

## When to avoid
- starting a new project - use resilience4j or similar instead
- you need adaptive, real-time performance-based concurrency limits
- you are not on the JVM
- you expect active maintenance, bug fixes, or new features

## Facets
- artifact type: library
- maturity: maintenance
- function: middleware, concurrency, monitoring, caching
- domain: microservices, backend, developer-tools, performance
- platform: jvm
- tags: fault-tolerance, circuit-breaker, resilience, latency, bulkhead, fallback, netflix-oss, java

## Member repositories
- Netflix/Hystrix (main) score 48

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:37.125671+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 2026-08-29T16:56:13.293586+00:00, confidence not recorded.
  - readme: https://github.com/Netflix/Hystrix (fetched 2026-08-28T04:11:37.125671+00:00, sha 40a3d2205fc1)
- Data as of 2026-08-30T08:39:29.467469+00:00.