pm2 cluster mode not outputting logs

Question

node: 12.13.0

pm2: 4.2.3

The issue is where nothing is printed in pm2-out and pm2-err log files instead of a few lines that pm2 prints the script which is executing. I tried both with Winston and Debug loggers. When I start in fork mode all logs are printed. Also, pm2 logs show the logs but files are empty.

I use merge_logs to avoid splitting out or err logs into multiple files per process.

I also tried with specifying log names but without luck. If anyone can help me, thank you in advance.

PS I don't want to use Winston output to file. Also, with pm2 monit I don't see anything.

ecosystem.config.js :

module.exports = {
 apps: [
    {
        name: 'client',
        script: 'npm',
        args: 'run start:client',
        cwd: '/mnt/data/app',
        watch: false,
        log_date_format: 'DD-MM-YYYY HH:mm',
        exec_mode: 'cluster',
        instances: '2',
        merge_logs: true,
        env: {
            PORT: 8080,
            NODE_ENV: 'production',
        },
    },
    {
        name: 'server',
        script: 'npm',
        args: 'run start:server',
        cwd: '/mnt/data/app',
        watch: false,
        log_date_format: 'DD-MM-YYYY HH:mm',
        exec_mode: 'cluster',
        instances: '2',
        merge_logs: true,
        env: {
            PORT: 3000,
            NODE_ENV: 'production',
           },
       },
    ],
};

Answer 1

run this command pm2 install pm2-intercom might work without this &

then add pm2: true in log4js config like the following :

log4js.configure({
    appenders: { 
        out: { 
            type: 'stdout'
        }
    },
    categories: { 
        default: { 
            appenders: ['out'], 
            level: 'info'
        }
    },
    pm2: true
});

for more details, refer https://github.com/log4js-node/log4js-node/blob/master/docs/clustering.md