Unable to create node script cluster with PM2

Question

I am trying to create node script cluster with PM2 but getting errors and its not working

Main node script in typescript

import express from 'express';
import mongoose from 'mongoose';

const app = express();

app.get('/', (req, res) => {
    const tickets = {};
    res.send(tickets);
});

const setup = async () => {
    console.clear();

    try {
        await mongoose.connect('mongodb://127.0.0.1:27017/tickets', {
            useNewUrlParser: true, 
            useUnifiedTopology: true,
            useCreateIndex: true
        });
    } catch(err) {
        console.log(err);
    } 

    app.listen(5001, () => {
        console.log('listing app on 5001');
    });
}

setup();

NPM run script

ts-node-dev --poll index.ts

My PM2 start script process.json

{
    "apps" : [
        {
            "name"       : "main-server",
            "script"     : "npm start",
            "autorestart": true,
            "instances"  : 4,
            "exec_mode"  : "cluster"            
        }
    ]
}

and getting error

SyntaxError: Invalid or unexpected token
3|main-ser |     at wrapSafe (internal/modules/cjs/loader.js:1047:16)
3|main-ser |     at Module._compile (internal/modules/cjs/loader.js:1097:27)
3|main-ser |     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1153:10)
3|main-ser |     at Module.load (internal/modules/cjs/loader.js:977:32)
3|main-ser |     at Function.Module._load (internal/modules/cjs/loader.js:877:14)
3|main-ser |     at /usr/local/lib/node_modules/pm2/lib/ProcessContainer.js:303:25
3|main-ser |     at wrapper (/usr/local/lib/node_modules/pm2/node_modules/async/internal/once.js:12:16)
3|main-ser |     at next (/usr/local/lib/node_modules/pm2/node_modules/async/waterfall.js:96:20)
3|main-ser |     at /usr/local/lib/node_modules/pm2/node_modules/async/internal/onlyOnce.js:12:16
3|main-ser |     at WriteStream.<anonymous> (/usr/local/lib/node_modules/pm2/lib/Utility.js:186:13)

When i am running direct command with single instance "ts-node-dev --poll index.ts" its working fine running with once instance. but with PM2 cluster mode its not working and app not loading.

Answer 1

I think you have to call the main script file differently. Before a while I tried to get a process file running. After spending a lot of time, it worked for me somehow. Give it a try with this configuration:

{
    "apps" : [
        {
            "name": "main-server",
            "script": "./index.ts",
            "node_args": [
                "ts-node-dev",
                "--poll"
            ],
            "autorestart": true,
            "instances": 4,
            "exec_interpreter": "node",
            "exec_mode": "cluster",
            "env": {
                "NODE_ENV": "development"
            },
            "env_production": {
                "NODE_ENV": "production"
            }
        }
    ]
}

• script is calling a file, not the npm command
• Arguments are given in node_args
• exec_interpreter is node or the whole path e.g. /usr/bin/nodejs
• not sure, but read anywhere to define env is important.

Run it in dev mode with pm2 start process.json and in prod mode with pm2 start process.json --env production.

Not tested. Good luck.