Akash

Akash is a Layer 4 load balancer written in Go. It supports multiple routing algorithms, active health checks, Prometheus metrics, TLS termination, and path-based routing.

⚠️ Warning: Akash is not production-ready. It was built purely for fun and learning purposes. It lacks stability, security, and robustness of a production-grade load balancer.

Website: akash.psidharth.dev

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Tech Stack

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Performance vs HAProxy (L4)

We benchmarked Akash against HAProxy, the industry standard L4 load balancer. The results show Akash performs on par with HAProxy in throughput and latency.

| Metric | Akash | HAProxy (L4) | | ---------------- | ------------ | ------------ | | Total Requests | 1,000,000 | 1,000,000 | | Throughput | 71,290 req/s | 71,585 req/s | | Median Latency | 2.1 ms | 1.7 ms | | 95th Percentile | 6.3 ms | 7.2 ms | | 99th Percentile | 12.1 ms | 14.7 ms | | Max Latency | 129 ms | 95.9 ms | | Data Transferred | 40 MB | 40 MB | | Success Rate | 99.995% | 99.995% |

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📊 Benchmark Insights

• Akash matches HAProxy in throughput (within ~0.5%).
• Latency distribution is nearly identical, with Akash slightly better at higher percentiles.
• Max latency spikes are different but within acceptable range.

For a Go-based project vs HAProxy’s C engine, Akash proves competitive.

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Features

• Routing Algorithms

  • Round Robin
  • Least Connections
  • IP Hash
  • Weighted Round Robin

• Health Checks

  • Regular TCP-based health checks
  • Automatic marking of backends as healthy/unhealthy

• Metrics

  • Exposes Prometheus metrics on :9100/metrics
  • Tracks active connections, per-backend requests, and per-backend failures

• TLS Support

  • Optional TLS termination with provided certificates

• Path-Based Routing

  • Route specific URL paths to specific backends

• Graceful Shutdown

  • Handles termination signals
  • Closes active connections before exit

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Getting Started

Prerequisites

• Go 1.21 or higher
• A valid config.json file (see example below)

Build

git clone https://github.com/your-username/akash.git
cd akash
go build -o akash

Run

./akash -config config.json

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Configuration

Akash is configured using a JSON file. Below is an example:

{
  "host": "0.0.0.0",
  "listen": "1902",
  "algorithm": "round_robin",
  "max_connections": 1000,
  "timeout_seconds": 5,
  "health_check_path": "/health",
  "health_check_port": "80",
  "health_check_freq": 10,
  "tls_cert_file": "server.crt",
  "tls_key_file": "server.key",
  "Backends": [
    {
      "address": "127.0.0.1:8081",
      "weight": 1,
      "paths": ["/api"]
    },
    {
      "address": "127.0.0.1:8082",
      "weight": 2,
      "paths": ["/static"]
    }
  ]
}

Config Fields

• host: Address to bind the load balancer (default: 0.0.0.0)
• listen: Port to listen on (default: 1902)
• algorithm: Routing algorithm (round_robin, least_conn, ip_hash, w_round_robin)
• max_connections: Maximum number of active connections
• timeout_seconds: Timeout for backend health checks
• health_check_path: Path for HTTP health checks
• health_check_port: Port for health checks
• health_check_freq: Frequency of health checks (in seconds)
• tls_cert_file / tls_key_file: Paths to TLS certificate and key
• Backends: List of backend servers with address, weight, and optional paths

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Metrics

Akash provides Prometheus-compatible metrics on :9100/metrics.

Exposed metrics include:

• akash_active_connections — Number of active client connections
• akash_backend_served_total{backend="..."} — Requests successfully served per backend
• akash_backend_failures_total{backend="..."} — Failed connections per backend

You can use Grafana to scrape metrics endpoint from Prometheus to build interactive dashboards

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Future Plans

Planned features:

• WebSocket support
• HTTP/2 and gRPC proxying
• Retry policies and circuit breakers
• Rate limiting per IP

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License

This project is licensed under the Apache 2.0 License.