reuseport

Documentation

Overview

Package reuseport provides TCP net.Listener with SO_REUSEPORT support.

SO_REUSEPORT allows linear scaling server performance on multi-CPU servers. See https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/ for more details :)

The package is based on https://github.com/kavu/go_reuseport .

Index

• func Listen(network, addr string) (net.Listener, error)
• type ErrNoReusePort
  • func (e *ErrNoReusePort) Error() string

Examples

• Listen

Functions

func Listen

func Listen(network, addr string) (net.Listener, error)

Listen returns TCP listener with SO_REUSEPORT option set.

The returned listener tries enabling the following TCP options, which usually have positive impact on performance:

• TCP_DEFER_ACCEPT. This option expects that the server reads from accepted connections before writing to them.

- TCP_FASTOPEN. See https://lwn.net/Articles/508865/ for details.

Use https://github.com/valyala/tcplisten if you want customizing these options.

Only tcp4 and tcp6 networks are supported.

ErrNoReusePort error is returned if the system doesn't support SO_REUSEPORT.

Example

package main

import (
	"fmt"
	"log"

	"github.com/valyala/fasthttp"
	"github.com/valyala/fasthttp/reuseport"
)

func main() {
	ln, err := reuseport.Listen("tcp4", "localhost:12345")
	if err != nil {
		log.Fatalf("error in reuseport listener: %s", err)
	}

	if err = fasthttp.Serve(ln, requestHandler); err != nil {
		log.Fatalf("error in fasthttp Server: %s", err)
	}
}

func requestHandler(ctx *fasthttp.RequestCtx) {
	fmt.Fprintf(ctx, "Hello, world!")
}

Types

type ErrNoReusePort

type ErrNoReusePort struct {
	// contains filtered or unexported fields
}

ErrNoReusePort is returned if the OS doesn't support SO_REUSEPORT.

func (*ErrNoReusePort) Error

func (e *ErrNoReusePort) Error() string

Error implements error interface.