Overview
HAProxy is a high-performance L4-L7 load balancer and proxy server written in C, focusing on stability and resource efficiency. Traefik is a modern HTTP reverse proxy and load balancer written in Go, designed specifically for cloud-native environments and microservices.
| Parameter | HAProxy | Traefik |
|---|---|---|
| Language | C | Go |
| Dynamic Config | Limited (Runtime API) | Native (Hot reload) |
| Service Discovery | DNS, Consul | Kubernetes, Docker, Consul, Etcd |
| Performance | Maximum (Low latency) | Moderate (Go GC overhead) |
| Interface | Stats page (text/CSV) | Web UI (Dashboard) |
| Protocols | TCP/HTTP/gRPC/QUIC | HTTP/gRPC/TCP/UDP |
Performance
HAProxy remains the benchmark for throughput. In bare-metal tests, HAProxy can handle over 2,000,000 requests per second (RPS) on a 16-core CPU with sub-millisecond latency. Traefik, due to Go's garbage collection and packet processing architecture, typically shows 20-30% lower throughput and higher p99 latencies under similar loads. HAProxy consumes 3-5 times less RAM for the same number of concurrent connections.
Configuration & complexity
HAProxy configuration is defined in a static haproxy.cfg file. Changes without restarts require the Runtime API or Data Plane API. Example: backend servers
server s1 10.0.0.1:80 check. Traefik operates on the principle of auto-discovery. Configuration is managed via Docker labels or Kubernetes CRDs. Example for Docker: traefik.http.routers.my-app.rule=Host(`example.com`). Traefik automatically updates routing tables as containers start or stop.
When to choose what
- HAProxy: High-load projects with static infrastructure, L4 traffic processing needs, strict latency requirements, or as an Ingress controller in massive clusters.
- Traefik: Dynamic environments (Kubernetes, Docker Swarm) where services scale frequently. Ideal for CI/CD pipelines and developer-centric workflows.
Cost / licensing
Both technologies offer Open Source versions under GPL (HAProxy) and MIT (Traefik) licenses. HAProxy Enterprise provides advanced security modules (WAF) and support. Traefik Enterprise includes distributed Let's Encrypt, advanced auth, and 24/7 support.
Ecosystem & integrations
HAProxy integrates with Prometheus via a built-in endpoint, supports Lua scripting, and SPOE (Stream Processing Offload Engine). Traefik features native Let's Encrypt support (automatic SSL), integrates with Jaeger and Zipkin, and has a Go-based plugin system.
Verdict
HAProxy is the choice for maximum hardware efficiency and predictability. Traefik is the choice for DevOps teams prioritizing deployment speed and cloud-native automation.