typescript cluster NodeJs

typescriptClusterNodeJs.ts

import cluster from "cluster";
import { cpus } from "os";

const NUM_WORKERS = cpus().length;
const PATH_TO_SERVER_APP = __dirname + '/app.ts';

cluster.setupMaster({
    execArgv: ['-r', 'tsconfig-paths/register', '-r', 'ts-node/register'],
    exec: PATH_TO_SERVER_APP
} as cluster.ClusterSettings)

var workers: { [key: string]: cluster.Worker } = {};

const closeCluster = () => {
    console.log('Master stopped');

    for (let pid in workers) {
        workers[pid].destroy('SIGTERM');
    }

    process.exit(0);
}

console.info('Cluster: Master cluster setting up ' + NUM_WORKERS + ' workers...');

for (var i = 0; i < NUM_WORKERS; i++) {
    let worker = cluster.fork();
    workers[worker.process.pid] = worker;

}

cluster.on('online', function (worker) {
    console.log('Cluster: Worker ' + worker.process.pid + ' is online');
});

cluster.on('exit', function (worker, code, signal) {
    console.log('Cluster: Worker ' + worker.process.pid + ' died with code: ' + code + ', and signal: ' + signal);
    console.log('Cluster: Starting a new worker');
    let newWorker = cluster.fork();

    workers[newWorker.process.pid] = newWorker;
});

// Master can be terminated by either SIGTERM
// or SIGINT. The later is used by CTRL+C on console.

//Note for nodemon. Use nodemon --signal SIGTERM
process.on('SIGTERM', closeCluster);
process.on('SIGINT', closeCluster);