Cluster

The Cluster plugin enables your Shokupan application to utilize multiple CPU cores, improving performance and reliability.

Features

• Multi-core Support: Automatically spawns workers based on available CPU cores.
• Bun Native: Leverages Bun.spawn and SO_REUSEPORT for worker distribution.
• Auto-Restart: Automatically restarts workers if they crash.

Installation

The Cluster plugin is included in the shokupan package.

import { Shokupan, ClusterPlugin } from 'shokupan';

const app = new Shokupan();

app.register(new ClusterPlugin({
    workers: 4 // number of workers, or 'auto'
}));

Configuration

The ClusterPlugin accepts the following options:

interface ClusterOptions {
    /**
     * Number of workers to spawn.
     * Set to -1 or 'auto' to spawn one worker per available CPU.
     * @default 'auto'
     */
    workers?: number | 'auto';

    /**
     * Whether to pipe stdout/stderr to the parent process.
     * @default false
     */
    silent?: boolean;

    /**
     * Enable sticky sessions (useful for Socket.io).
     * @default false
     */
    sticky?: boolean;
}

How It Works

In Bun, the plugin uses Bun.spawn to create worker processes. It leverages Bun’s native reusePort functionality, allowing multiple workers to listen on the same port and having the kernel distribute incoming connections.