pm2

The pm2 plugin reports every process the local PM2 daemon manages. Each process becomes its own service with its status, CPU, memory and restart count. Turn it on for hosts that run Node apps under PM2.

Enable it

Add pm2 to the plugins array.

{
  "plugins": ["pm2"],
  "pm2": {
    "refreshInterval": 10000
  }
}

Option	Default	What it does
refreshInterval	5000	Milliseconds between reports.

The example config and the client README list a processes option. The plugin does not read it. It always reports every process in pm2 list.

Keep the pm2 section in the config even if it is empty. The plugin reads config.refreshInterval without a null check, so a missing section throws when monitoring starts.

What it reports

One payload per PM2 process, per interval. The unique id is pm2-<name>-<n>, where n counts instances of the same name, so a cluster-mode app with four instances reports as four services.

• name, pm_id, pid.
• status, PM2's own value: online, stopping, stopped, launching, errored or one-launch-status.
• monit.cpu in percent and monit.memory in bytes.
• restarts (same value as restart_time) and unstable_restarts.
• pm_uptime, created_at, autorestart, watch, username, node_version.

When it alerts

Condition	Severity
status is errored	error
status is anything else other than online	warning

The reason reads <name> is <status>.

A new problem does not notify on the first bad report. The server holds it until a second consecutive report from the same process is still bad, then sends the alert. When the process reports online again, the server resolves the alert.

On the dashboard

The card is titled with the process name and labelled Node · PM2.

Reading	Source	Warn	Crit
CPU bar	monit.cpu	above 70%	above 85%
STATUS	status, upper-cased	see below	see below
MEM	monit.memory	none	none
RESTARTS	restarts	more than 5	none

The STATUS metric is green for online. The dashboard does not map PM2's other words, so stopped and errored both show grey on that metric. The card's own color follows the server's verdict, so an errored process still shows a red card. CPU pressure raises the card color for display only.

A process that has not reported for 300 seconds shows OFFLINE.

Requirements

• The agent must run as the user that owns the PM2 daemon, so it can connect to that daemon.
• The pm2 npm package, which the plugins package installs as a dependency.

The client README notes that the pm2 plugin does not work when the agent runs as a systemd service.

Gotchas

• If the plugin cannot connect to PM2 at startup, it throws during setup. Setup runs for all plugins in sequence, so the failure stops the whole agent from starting, not only pm2.
• The first report arrives one interval after startup. Unlike most plugins, pm2 does not send a report immediately.
• The RESTARTS count is PM2's lifetime counter for the process, so a long-lived process can sit above 5 and stay amber.