# github/glb-director

GitHub Load Balancer Director and supporting tooling.

Repository: https://github.com/github/glb-director
Canonical: https://ross.abutalabs.com/products/glb-director
Language: C
License: NOASSERTION
License Family: other
Last push: 2026-08-24T01:43:45+00:00

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 8, longevity 100
- inputs: {"age_days": 3030, "days_push": 10, "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 2453, forks 239 (observed 2026-08-28T04:06:52.975221+00:00)

## What it is
GitHub's GLB Director is a set of components implementing a scalable, stateless Layer 4 load balancer for bare metal datacenter environments, using rendezvous hashing and UDP encapsulation with Direct Server Return. It is used in production to serve all traffic from GitHub's datacenters.

## Use cases
- build a scalable layer 4 load balancer for a datacenter
- distribute traffic across servers using ECMP and BGP anycast
- handle line-rate packet processing on bare metal
- implement a split L4/L7 load balancing architecture
- avoid flow state sharing between load balancer nodes
- drain servers without disrupting existing connections

## When to choose
- you operate bare metal datacenter infrastructure with ECMP routing
- you need a stateless L4 director tier with flow-aware redirection
- you want a production-proven load balancer design from GitHub

## When to avoid
- you need a simple software load balancer for cloud VMs or containers
- you require Layer 7 (HTTP) load balancing features
- you lack control over network routing (BGP/ECMP) in your environment

## Facets
- artifact type: library
- maturity: maintenance
- function: networking, proxy, load-testing
- domain: networking, infrastructure-as-code, microservices, developer-tools
- platform: c, self-hosted
- tags: load-balancer, layer4, ecmp, dpdk, gue-encapsulation, datacenter, bgp, direct-server-return, linux

## Member repositories
- github/glb-director (main) score 67

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:52.975221+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 2026-08-30T02:30:08.953240+00:00, confidence not recorded.
  - readme: https://github.com/github/glb-director (fetched 2026-08-28T04:06:52.975221+00:00, sha 1038730480f0)
- Data as of 2026-08-30T08:39:29.467469+00:00.