node-unix-socket

npm_bandage

node-unix-socket allows you to use some nonblocking unix sockets that are currently not supported by Node.js native modules, including:

unix seqpacket(SOCK_SEQPACKET) sockets
unix datagram(SOCK_DGRAM) sockets
Using SO_REUSEPORT enabled TCP net.Server

node-unix-socket is a napi-rs based Node.js addons and:

This lib bases on n-api and is pre-compiled so that it doesn’t require compilation environments if yours is pre-built supported.
This lib won’t introduce any other asynchronous runtimes as it uses libuv inside Node.js.

We use SOCK_SEQPACKET sockets for in our internal APM.

Tested Platforms & Node.js

Platform	Node.js	DgramSocket	Seqpacket
x64 Linux	12 + LTS	✅	✅
x64 Darwin	12 + LTS	✅
aarch64 Darwin	12 + LTS	✅

Installation

npm i node-unix-socket

API Documents

Seqpacket Sockets

SOCK_SEQPACKET sockets are like SOCK_STREAM sockets while they keep message boundaries.

Note that SOCK_SEQPACKET sockets don’t work on MacOS.

Example

Online Example

const { SeqpacketServer, SeqpacketSocket } = require('node-unix-socket');
const os = require('os');
const path = require('path');
const fs = require('fs');

const bindPath = path.resolve(os.tmpdir(), './my_seqpacket.sock');

try {
  fs.unlinkSync(bindPath);
} catch (e) {}

const server = new SeqpacketServer();
server.listen(bindPath);
server.on('connection', (socket) => {
  socket.on('data', (buf) => {
    console.log('received', buf.toString());
  });
});

const client = new SeqpacketSocket();
client.connect(bindPath, () => {
  const data = ['hello, ', 'w', 'o', 'r', 'l', 'd'];

  for (const str of data) {
    client.write(Buffer.from(str));
  }
  client.end();
});

Dgram Sockets

Example

Online Example

const { DgramSocket } = require('node-unix-socket');
const os = require('os');
const path = require('path');
const fs = require('fs');

const path1 = path.resolve(os.tmpdir(), './my_dgram_1.sock');
const path2 = path.resolve(os.tmpdir(), './my_dgram_2.sock');

try {
  fs.unlinkSync(path1);
  fs.unlinkSync(path2);
} catch (err) {}

const socket1 = new DgramSocket();
const socket2 = new DgramSocket();

socket1.bind(path1);
socket2.bind(path2);

socket2.on('data', (data, remoteAddr) => {
  console.log(`socket2 received: ${data.toString()}`);
  // echo
  socket2.sendTo(data, 0, data.length, remoteAddr);
});

socket1.on('data', (data) => {
  console.log(`socket1 received: ${data.toString()}`);
});

setInterval(() => {
  const buf = Buffer.from('hello');
  socket1.sendTo(buf, 0, buf.length, path2);
}, 1000);

`SO_REUSEPORT` enabled TCP net.Server

The cluster module share server ports by accepting new connections in the primary process and distributing them to worker processes.

With SO_REUSEPORT, sockets will be distributed by kernel instead, and which should be more performant especially for scenario of having a lot of short-lived connections.

For example, the arrow in the image below shows cpu usage of a PM2 primary process which we found in our environment.

cpu_usage

Note that SO_REUSEPORT might behave much differently across operating systems. See this post for more information.

Example

Online Http Server Example

const { createReuseportFd } = require('node-unix-socket');
const { Server, Socket } = require('net');

const port = 8080;
const host = '0.0.0.0';

// create multple servers listening to a same host, port.
for (let i = 0; i < 2; i += 1) {
  const fd = createReuseportFd(port, host);
  const server = new Server((socket) => {
    socket.on('data', (buf) => {
      console.log(`server ${i} received:`, buf);
      // echo
      socket.write(buf);
    });
  });

  server.listen(
    {
      fd,
    },
    () => {
      console.log(`server ${i} is listening on ${port}`);
    }
  );
}

setInterval(() => {
  const client = new Socket();
  client.on('data', (buf) => {
    console.log('client received:', buf);
    client.destroy();
  });
  client.connect(port, host, () => {
    client.write(Buffer.from('hello'));
  });
}, 1000);