NestJS clustering via NodeJS workers

cluster.service.ts

import cluster from "node:cluster";
import { Injectable } from "@nestjs/common";
import { cpuCountSync } from "node-cpu-count";

const numCPUs = cpuCountSync();

@Injectable()
export class AppClusterService {
  static register(callback: () => void): void {
    if (cluster.isPrimary) {
      console.log(`Master server started on ${process.pid}`);
      for (let i = 0; i < numCPUs; i++) {
        cluster.fork();
      }
      cluster.on("exit", (worker, code, signal) => {
        console.log(`Worker ${worker.process.pid} died. Restarting`);
        console.log({
          code,
          signal,
        });
        cluster.fork();
      });
    } else {
      console.log(`Cluster server started on ${process.pid}`);
      callback();
    }
  }
}