---
Title: 'throngでwebサーバーをクラスタリング #nodejs #express #heroku'
Keywords:
  - nodejs
  - express
  - heroku
Author: hiro_y
Web: 'https://mimemo.io/m/WrRz7l7QKGNaA6n'
---

HerokuでNode.jsのアプリをExpressで作って、クラスタリングを試すのに[throng](https://github.com/hunterloftis/throng)を使ったのでwebサーバーの起動方法をメモ

```js
const throng = require('throng');

// 中略

throng({
  workers: config.webConcurrency,
  lifetime: Infinity,
  master: () => {
    console.log('Started master');
  },
  start: (id) => {
    app.listen(config.port, () => {
      console.log(`Started worker ${id} on port: ${config.port}`);
    });
    process.on('SIGTERM', () => {
      console.log(`Worker ${id} exiting...`);
      process.exit();
    });
  },
});
```

参考: [Optimizing Node.js Application Concurrency | Heroku Dev Center](https://devcenter.heroku.com/articles/node-concurrency)