Swindlr is a load balancer designed to distribute traffic efficiently across multiple backend servers. It supports a variety of features including response caching, SSL/TLS termination, dynamic backend management, multiple load balancing strategies, sticky sessions and rate limiting . This document describes the configuration options available for Swindlr.

Swindlr Load Balancer Configuration

This document outlines the configuration options available for the Swindlr load balancer. The configuration is managed using Viper and can be set via a configuration file, environment variables, or command-line flags.

Configuration Options

General Settings

• port: The port on which the load balancer will listen for incoming HTTP requests.

  • Default: 8080
  • Environment Variable: PORT

• backends: A list of backend server URLs that the load balancer will distribute traffic to.

  • Default: []
  • Environment Variable: BACKENDS

SSL/TLS Settings

• use_ssl: Enable or disable SSL/TLS for the load balancer.

  • Default: false
  • Environment Variable: USE_SSL

• ssl_cert_file: Path to the SSL certificate file.

  • Default: ""
  • Environment Variable: SSL_CERT_FILE

• ssl_key_file: Path to the SSL key file.

  • Default: ""
  • Environment Variable: SSL_KEY_FILE

Dynamic Backend Management

• use_dynamic: Enable or disable dynamic management of backend servers via API.

  • Default: false
  • Environment Variable: USE_DYNAMIC

• apiPort: The port on which the API server for dynamic backend management will listen.

  • Default: 8082
  • Environment Variable: API_PORT

Load Balancing Strategy

• load_balancer.strategy: The strategy used for load balancing. Valid options are:
  • round_robin
  • least_connections
  • random
  • latency_aware - chooses a backend depending on the latency. The latency is recorded periodically.
  • Default: round_robin
  • Environment Variable: LOAD_BALANCER_STRATEGY

Sticky Sessions

• use_sticky_sessions: Enable or disable sticky sessions, which bind a client to a specific backend server.
  • Default: false
  • Environment Variable: USE_STICKY_SESSIONS

Rate Limiting

• rate_limiting.rate: The rate at which requests are allowed to pass through the rate limiter (requests per second).

  • Default: 10.0
  • Environment Variable: RATE_LIMITING_RATE

• rate_limiting.bucket_size: The maximum number of requests that can be allowed to pass through the rate limiter in a burst.

  • Default: 5
  • Environment Variable: RATE_LIMITING_BUCKET_SIZE

Caching

• use_cache: Enable or disable caching of responses.
  • Default: false
  • Environment Variable: USE_CACHE

Example Configuration File

Below is an example config.yaml file that sets various configuration options:

port: 8080
backends:
  - http://backend1.example.com
  - http://backend2.example.com
use_ssl: true
ssl_cert_file: "/path/to/cert.pem"
ssl_key_file: "/path/to/key.pem"
use_dynamic: true
apiPort: 8082
load_balancer:
  strategy: least_connections
use_sticky_sessions: true
rate_limiting:
  rate: 20.0
  bucket_size: 10
use_cache: true