Cron Restarts

pm3 supports scheduled restarts via standard cron expressions. This is useful for long-running processes that benefit from periodic refreshes — clearing caches, releasing memory, or rotating connections.

Configuration

[worker]
command = "node worker.js"
cron_restart = "0 3 * * *"

Type: string — a standard 5-field cron expression.

Cron Syntax

┌───────── minute (0-59)
│ ┌─────── hour (0-23)
│ │ ┌───── day of month (1-31)
│ │ │ ┌─── month (1-12)
│ │ │ │ ┌─ day of week (0-6, Sunday = 0)
│ │ │ │ │
* * * * *

Examples

Behavior

• Timezone: Cron schedules are evaluated in UTC.
• Graceful restart: When triggered, pm3 performs a graceful stop (sends kill_signal, waits kill_timeout, runs post_stop hook) then respawns the process.
• Restart counter: Cron restarts are preserved in the restart counter — they do count toward max_restarts.

Example

[cache-worker]
command = "python cache_worker.py"
restart = "always"
cron_restart = "0 */6 * * *"
max_memory = "256M"

This worker restarts every 6 hours and also restarts if it exceeds 256MB of memory.