Loadbalancer in Golang

About the project

This project is intended for education purpose only and not suitable for production use. If you have constructive feedback please let me know.

Usage

Describe load balancing ports and targets in config.yaml. See example config file.

package main

import (
	"log"

	loadbalancer "gitlab.com/vorozhko/loadbalancer/loadbalancer"
)

func main() {
	server := loadbalancer.LoadBalancer{}
	err := server.Start("config.yaml")
	if err != nil {
		log.Fatal(err)
	}
}

Roadmap

Milestone 0 (Release 0.0.1)

Prototype first load balancer version

Milestone 1 (Release 0.0.2)

Design code structure
Impleement round roubin load balancing

Milestone 2 (Release 0.0.3)

YAML: Load multi listeners and backend servers endpoints
Store servers status: up/down
Exlcude down servers
Least connections algorithm
Content based routing
Sticky sessions support

Milestone 3 (Release 0.0.4)

Refactor upstream selection
Refactor health checker

Milestone 4

Retry on error
Request parsing: client ip, host, port, path
HTTP compression
Error handling - show custom error message to user
Content filtering - modify request content by some rules

Features list

Requests handling

Request parsing: client ip, host, port, path
TLS termination
DDOS protection

Backend server selection

Exclude down servers
Check if persistent session enabled
Content based routing - /video and /images go to different servers
Assymetric load - if manual weight for servers is set
Select best of 2 random servers
Least connections
Backend server load - get reported by application response headers if present
Response time

Upstream requests

HTTP compression
Error handling - show custom error message to user
Content filtering - modify request content by some rules
Retry on error
2nd backend server on error - use second best backend server from server selection step

Persistent data

Servers status: up/down
Servers load
Servers connections
Servers resposne time: median, 95pt, 99pt for past 5 minutes
Monitoring: response time, network IO, status codes, errors rate
Storage VaultDB

Loadbalancer manager

YAML: config file to manage LB settings
YAML: Load multi listeners and backend servers endpoints
YAML: Load persistent settings
YAML: Load manual weights for backend servers
Re-read config file by SIGNAL

Infrastructure

Add Docker support
Run in distiributed HA pairs
Share state between HA pairs
Add Kubernetes support

Releases

Release 0.0.1

Added: YAML config file to manage LB settings
Added: Load single listener and multiple backend servers
Added: Least connections algorithm for servers selection

Release 0.0.2

New code structure
Impleemented round roubin load balancing

Release 0.0.3

Added support for multiple target groups on the same port split by request Path
Added content based routing. See Path in YAML file.
Added health check monitor
Exlcude down servers from upstream selection
Implemented Least connections algorithm
Added support for sticky sessions

Release 0.0.4

Refactoring of upstream selection and health checker

vorozhko / go-loadbalancr-proxy