Divisor

A fast and easy-to-configure load balancer

Table of Contents

1. About The Project
2. Features
3. Installation
4. Usage
5. Configuration
6. Limitations
7. Benchmark
8. TODO
9. Contributors
10. License

About The Project

This project is designed to provide a fast and easy-to-configure load balancer in Go language. It currently includes round-robin, weighted round-robin, least-connection, least-response-time, ip-hash and random algorithms, but we have more to add to our TODO list.

The project is developed using the fasthttp library, which ensures high performance. Its purpose is to distribute the load evenly among multiple servers by routing incoming requests.

The project aims to simplify the configuration process for users while performing the essential functions of load balancers. Therefore, it offers several configuration options that can be adjusted to meet the users needs.

This project is particularly suitable for large-scale applications and websites. It can be used for any application that requires a load balancer, thanks to its high performance, ease of configuration, and support for different algorithms.

Features

• Fast and easy-to-configure load balancer.
• Supports round-robin, weighted round-robin, least-connection, least-response-time, IP hash, and random algorithms.
• Supports TLS and HTTP/2 for the frontend server.
• Uses the fasthttp library for high performance and scalability.
• Offers multiple configuration options to suit user needs.
• Can handle large-scale applications and websites.
• Includes a built-in monitoring system that displays real-time information on the system's CPU usage, RAM usage, number of Goroutines, and open connections.
• Prometheus support for monitoring. (http://monitoring-host:monitoring-port/metrics can be used to get prometheus metrics)
• Provides information on each server's average response time, total request count, and last time used.
• Lightweight and efficient implementation for minimal resource usage.

Installation

Downloading the Release

The latest release of Divisor can be downloaded from the releases page. Choose the suitable binary for your system, download and extract the archive, and then move the binary to a directory in your system's $PATH variable (e.g. /usr/local/bin).

Building from Source

Alternatively, you can build Divisor from source by cloning this repository to your local machine and running the following commands:

git clone https://github.com/aaydin-tr/divisor.git &&
cd divisor &&
go build -o divisor &&
./divisor

Using go install

You can also install Divisor using the go install command:

go install github.com/aaydin-tr/divisor@latest

This will install the divisor binary to your system's $GOPATH/bin directory. Make sure this directory is included in your system's $PATH variable to make the divisor accessible from anywhere.

That's it! You're now ready to use Divisor in your project.

Usage

You need a config.yaml file to use Divisor, you can give this file to Divisor to use with the --config flag, by default it will try to use a config.yaml file in the directory it is in. Example config files

⚠️ Please use absolute path for "config.yaml" while using "--config" flag

Configuration

Name	Description	Type	Default Value
type	Load balancing algorithm	string	round-robin
port	Server port	int	8000
host	Server host	string	localhost
health_checker_time	Time interval to perform health check for backends	time.Duration	30s
backends	List of backends with their configurations	array
backends.url	Backend URL	string
backends.health_check_path	Health check path for backends	string	/
backends.weight	Only mandatory for w-round-robin algorithm	int
backends.max_conn	Maximum number of connections which may be established to host listed in Addr	int	512
backends.max_conn_timeout	Maximum duration for waiting for a free connection	time.Duration	30s
backends.max_conn_duration	Keep-alive connections are closed after this duration	time.Duration	10s
backends.max_idle_conn_duration	Idle keep-alive connections are closed after this duration	time.Duration	10s
backends.max_idemponent_call_attempts	Maximum number of attempts for idempotent calls	int	5
monitoring	Monitoring server configurations	object
monitoring.port	Monitoring server port	int	8001
monitoring.host	Monitoring server host	string	localhost
custom_headers	Custom headers will be set on request sent to backend	object
custom_headers.header-name	Valid values are $remote_addr, $time, $incremental, $uuid, The Header name can be whatever you want as long as it's a string	string
server	Server configurations	object
server.http_version	Http version for frontend server, http1 and http2 is supported (http1 mean HTTP/1.1)	string	http1
server.cert_file	TLS cert file	string
server.key_file	TLS key file	string
server.max_idle_worker_duration	MaxIdleWorkerDuration is the maximum idle time of a single worker in the underlying worker pool of the Server	time.Duration	10s
server.tcp_keepalive_period	Period between tcp keep-alive messages. TCP keep-alive period is determined by operation system by default	time.Duration
server.concurrency	The maximum number of concurrent connections the server may serve	int	262144
server.read_timeout	ReadTimeout is the amount of time allowed to read the full request including body	time.Duration	unlimited
server.write_timeout	WriteTimeout is the maximum duration before timing out writes of the response	time.Duration	unlimited
server.idle_timeout	IdleTimeout is the maximum amount of time to wait for the next request when keep-alive is enabled	time.Duration	unlimited
server.disable_keepalive	The server will close all the incoming connections after sending the first response to client if this option is set to true	bool	false
server.disable_header_names_normalizing	Header names are passed as-is without normalization if this option is set true	bool	false

Please see example config files

Limitations

While Divisor has several features and benefits, it also has some limitations to be aware of:

• Divisor currently operates at layer 7, meaning it is specifically designed for HTTP(S) load balancing. It does not support other protocols, such as TCP or UDP.
• Divisor does not support HTTP/3, which may be important for some applications.
• Divisor does not support HTTPS for backend servers. HTTPS only available for frontend server.

Please keep these limitations in mind when considering whether this load balancer is the right choice for your project.

Benchmark

Please see the benchmark folder for detail explanation

TODO

While Divisor has several features, there are also some areas for improvement that are planned for future releases:

• Add support for other protocols, such as TCP or UDP.
• Add TLS support for frontend.
• Support HTTP/2 in frontend server.
• Add more load balancing algorithms, such as,
  • least connection
  • least-response-time
  • sticky round-robin
• Improve performance and scalability for high-traffic applications.
• Expand monitoring capabilities to provide more detailed metrics and analytics.

By addressing these issues and adding new features, we aim to make Divisor an even more versatile and powerful tool for managing traffic in modern web applications.

Contributors

License

This project is licensed under the MIT License. See the LICENSE file for more information.

The MIT License is a permissive open-source software license that allows users to modify and redistribute the code, as long as the original license and copyright notice are included. This means that you are free to use Divisor for any purpose, including commercial projects, without having to pay any licensing fees or royalties. However, it is provided "as is" and without warranty of any kind, so use it at your own risk.