Log management

Logs are available at realtime and are saved into your hard disk.

The way your logs are formatted, the way log files are created: everything can be customized.

Access the logs

Real-time logs

# all apps logs
pm2 logs

# only app logs
pm2 logs app

Log files

By default, all logs are saved into $HOME/.pm2/logs.

You can empty all application logs with:

pm2 flush

Log files configuration

You can specify a custom location for your logs.

module.exports = {
  apps: [{
      name: 'app',
      script: 'app.js',
      output: './out.log',
      error: './error.log',
	    log: './combined.outerr.log',
    }]
}

output is only standard output (console.log)
error is only error output (console.error)
log combines output and error, disabled by default

Rotating Logs

If you want to split logs into multiple files instead of a big one, use the logrotate:

pm2 install pm2-logrotate

Learn how to configure the module here.

Merging Logs

In cluster mode, each cluster has his own log files. You can use the merge options to gather all logs into a single file:

module.exports = {
  apps: [{
      name: 'app',
      script: 'app.js',
      output: './out.log',
      error: './error.log',
      merge_logs: true,
    }]
}

Logs are still splitted into output/error/log

Disabling Logs

You can disable logs by sending them to /dev/null:

module.exports = {
  apps: [{
      name: 'app',
      script: 'app.js',
      output: '/dev/null',
      error: '/dev/null',
    }]
}

Log formating

JSON

You can output the logs in JSON format:

Hello World!

becomes:

{
   "message": "Hello World!\n",
   "timestamp": "2017-02-06T14:51:38.896Z",
   "type": "out",
   "process_id": 0,
   "app_name": "app"
}

Add this entry in your ecosystem file:

ecosystem file: “log_type”: “json”`

Timestamp format

You can output the logs adding a timestamp:

Hello World!

becomes:

12-02-2018: Hello World!

Add this entry in your ecosystem file:

"log_date_format": "DD-MM-YYYY"

The format must follow a moment.js format, list here.

Next Steps

Startup Hook