NBIO - NON-BLOCKING IO

Recommendation

Based on years of development and testing of nbio, I have drawn some conclusions:

For massive connection scenarios, combined with memory pools and goroutine pools, it can effectively reduce the number of goroutines and objects, thereby lowering memory consumption and GC pressure, avoiding OOM and significant STW. For example, in a million WebSocket 1k payload echo test, nbio can maintain memory at 1GB with 100k TPS.

For regular connection scenarios, nbio's performance is inferior to the standard library due to goroutine affinity, lower buffer reuse rate for individual connections, and variable escape issues.

The vast majority of business scenarios using Golang do not require support for massive connections. The few scenarios that do require massive connections are mostly infrastructure such as gateways and proxies, and these types of infrastructure have higher requirements for performance and hardware resource overhead, where C/C++/Rust are more suitable.

Therefore, the scenarios where nbio can demonstrate its advantages are very limited.

For WebSocket in regular connection scenarios

I recommend: - https://github.com/lxzan/gws - https://github.com/antlabs/quickws

While gorilla/websocket is mature and stable, its default ReadMessage performance is poor, and it requires additional encapsulation for reading and writing to avoid consistency issues, concurrent timing problems, and the issue where a single connection's write blocking in broadcast scenarios causes other connections to wait.

nbio, gws and quickws all provide better out-of-the-box designs, which spare users the trouble of doing more encapsulation work on gorilla/websocket.

However, as mentioned above, nbio has no advantage in regular connection scenarios, and it supports more features with more complex compatibility code. Its performance in regular connection scenarios is inferior to gws and quickws, so I recommend gws and quickws.

Some other well-implemented epoll libs

nbio's functionality is somewhat complex.

If anyone is just interested in exploring the epoll wrapper part, I recommend: - https://github.com/urpc/uio - https://github.com/antlabs/pulse

Contents

• NBIO - NON-BLOCKING IO
  • Recommendation
    • For WebSocket in regular connection scenarios
    • Some other well-implemented epoll libs
  • Contents
  • Features
    • Cross Platform
    • Protocols Supported
    • Interfaces
  • Quick Start
  • Examples
    • TCP Echo Examples
    • UDP Echo Examples
    • TLS Examples
    • HTTP Examples
    • HTTPS Examples
    • Websocket Examples
    • Websocket TLS Examples
    • Use With Other STD Based Frameworkds
    • More Examples
  • 1M Websocket Connections Benchmark
  • Magics For HTTP and Websocket
    • Different IOMod
    • Using Websocket With Std Server
  • Credits
  • Contributors
  • Star History

Features

Cross Platform

• [x] Linux: Epoll with LT/ET/ET+ONESHOT supported, LT as default
• [x] BSD(MacOS): Kqueue
• [x] Windows: Based on std net, for debugging only

Protocols Supported

• [x] TCP/UDP/Unix Socket supported
• [x] TLS supported
• [x] HTTP/HTTPS 1.x supported
• [x] Websocket supported, Passes the Autobahn Test Suite, OnOpen/OnMessage/OnClose order guaranteed

Interfaces

• [x] Implements a non-blocking net.Conn(except windows)
• [x] SetDeadline/SetReadDeadline/SetWriteDeadline supported
• [x] Concurrent Write/Close supported(both nbio.Conn and nbio/nbhttp/websocket.Conn)

Quick Start

package main

import (
    "log"

    "github.com/lesismal/nbio"
)

func main() {
    engine := nbio.NewEngine(nbio.Config{
        Network:            "tcp",//"udp", "unix"
        Addrs:              []string{":8888"},
        MaxWriteBufferSize: 6 * 1024 * 1024,
    })

    // handle new connection
    engine.OnOpen(func(c *nbio.Conn) {
        log.Println("OnOpen:", c.RemoteAddr().String())
    })
    // handle connection closed
    engine.OnClose(func(c *nbio.Conn, err error) {
        log.Println("OnClose:", c.RemoteAddr().String(), err)
    })
    // handle data
    engine.OnData(func(c *nbio.Conn, data []byte) {
        c.Write(append([]byte{}, data...))
    })

    err := engine.Start()
    if err != nil {
        log.Fatalf("nbio.Start failed: %v\n", err)
        return
    }
    defer engine.Stop()

    <-make(chan int)
}

Examples

TCP Echo Examples

• echo-server
• echo-client

UDP Echo Examples

• udp-server
• udp-client

TLS Examples

• tls-server
• tls-client

HTTP Examples

• http-server
• http-client

HTTPS Examples

• http-tls_server
• visit: https://localhost:8888/echo

Websocket Examples

• websocket-server
• websocket-client

Websocket TLS Examples

• websocket-tls-server
• websocket-tls-client

Use With Other STD Based Frameworkds

• echo-http-and-websocket-server
• gin-http-and-websocket-server
• go-chi-http-and-websocket-server

More Examples

• nbio-examples

1M Websocket Connections Benchmark

For more details: go-websocket-benchmark

# lsb_release -a
LSB Version:    core-11.1.0ubuntu2-noarch:security-11.1.0ubuntu2-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.6 LTS
Release:        20.04
Codename:       focal

# free
              total        used        free      shared  buff/cache   available
Mem:       24969564    15656352     3422212        1880     5891000     8899604
Swap:             0           0           0

# cat /proc/cpuinfo | grep processor
processor       : 0
processor       : 1
processor       : 2
processor       : 3
processor       : 4
processor       : 5
processor       : 6
processor       : 7
processor       : 8
processor       : 9
processor       : 10
processor       : 11
processor       : 12
processor       : 13
processor       : 14
processor       : 15


# taskset
run nbio_nonblocking server on cpu 0-7

--------------------------------------------------------------
BenchType  : BenchEcho
Framework  : nbio_nonblocking
TPS        : 104713
EER        : 280.33
Min        : 56.90us
Avg        : 95.36ms
Max        : 2.29s
TP50       : 62.82ms
TP75       : 65.38ms
TP90       : 89.38ms
TP95       : 409.55ms
TP99       : 637.95ms
Used       : 47.75s
Total      : 5000000
Success    : 5000000
Failed     : 0
Conns      : 1000000
Concurrency: 10000
Payload    : 1024
CPU Min    : 0.00%
CPU Avg    : 373.53%
CPU Max    : 602.33%
MEM Min    : 978.70M
MEM Avg    : 979.88M
MEM Max    : 981.14M
--------------------------------------------------------------

Magics For HTTP and Websocket

Different IOMod

IOMod	Remarks
IOModNonBlocking	There's no difference between this IOMod and the old version with no IOMod. All the connections will be handled by poller.
IOModBlocking	All the connections will be handled by at least one goroutine, for websocket, we can set Upgrader.BlockingModAsyncWrite=true to handle writing with a separated goroutine and then avoid Head-of-line blocking on broadcasting scenarios.
IOModMixed	We set the Engine.MaxBlockingOnline, if the online num is smaller than it, the new connection will be handled by single goroutine as IOModBlocking, else the new connection will be handled by poller.

The IOModBlocking aims to improve the performance for low online service, it runs faster than std. The IOModMixed aims to keep a balance between performance and cpu/mem cost in different scenarios: when there are not too many online connections, it performs better than std, or else it can serve lots of online connections and keep healthy.

Using Websocket With Std Server

package main

import (
    "fmt"
    "net/http"

    "github.com/lesismal/nbio/nbhttp/websocket"
)

var (
    upgrader = newUpgrader()
)

func newUpgrader() *websocket.Upgrader {
    u := websocket.NewUpgrader()
    u.OnOpen(func(c *websocket.Conn) {
        // echo
        fmt.Println("OnOpen:", c.RemoteAddr().String())
    })
    u.OnMessage(func(c *websocket.Conn, messageType websocket.MessageType, data []byte) {
        // echo
        fmt.Println("OnMessage:", messageType, string(data))
        c.WriteMessage(messageType, data)
    })
    u.OnClose(func(c *websocket.Conn, err error) {
        fmt.Println("OnClose:", c.RemoteAddr().String(), err)
    })
    return u
}

func onWebsocket(w http.ResponseWriter, r *http.Request) {
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        panic(err)
    }
    fmt.Println("Upgraded:", conn.RemoteAddr().String())
}

func main() {
    mux := &http.ServeMux{}
    mux.HandleFunc("/ws", onWebsocket)
    server := http.Server{
        Addr:    "localhost:8080",
        Handler: mux,
    }
    fmt.Println("server exit:", server.ListenAndServe())
}

Credits

• xtaci/gaio
• gorilla/websocket
• crossbario/autobahn

Contributors

Thanks Everyone: - acgreek - acsecureworks - arunsathiya - byene0923 - guonaihong - isletnet - liwnn - manjun21 - maxkidd - om26er - rfyiamcool - sunny352 - sunvim - wuqinqiang - wziww - yicixin - [youzhixiaomutou](https: