zombie-killer

by @Dunc4nJ in AI & LLM

# Install this skill:

npx skills add Dunc4nJ/agent-skills --skill "zombie-killer"

Install specific skill from multi-skill repository

# Description

Detect and kill zombie processes on the VPS. Use when the user mentions zombies, defunct processes, slow VPS, high load average, stale agent sessions, or process cleanup. Triggers on "check zombies", "kill zombies", "why is my server slow", "clean up processes", "defunct processes".

# SKILL.md

name: zombie-killer
description: Detect and kill zombie processes on the VPS. Use when the user mentions zombies, defunct processes, slow VPS, high load average, stale agent sessions, or process cleanup. Triggers on "check zombies", "kill zombies", "why is my server slow", "clean up processes", "defunct processes".
allowed-tools: Bash(zombie-killer:*)

Zombie Process Killer

Detects zombie (defunct) processes, identifies their parent processes, kills stale parents to reap them, and optionally installs a cron job for ongoing monitoring.

Quick Reference

# Scan for zombies (default)
~/.agents/skills/zombie-killer/scripts/zombie-killer.sh scan

# Kill parent processes holding zombies
~/.agents/skills/zombie-killer/scripts/zombie-killer.sh kill

# Install cron monitoring (every 30 min)
~/.agents/skills/zombie-killer/scripts/zombie-killer.sh install-cron

# Remove cron monitoring
~/.agents/skills/zombie-killer/scripts/zombie-killer.sh uninstall-cron

# Check config, cron status, recent alerts
~/.agents/skills/zombie-killer/scripts/zombie-killer.sh status

Commands

Command	What it does
`scan`	Lists all zombies, groups by parent PID, shows parent command
`kill`	Sends SIGTERM (then SIGKILL) to parent processes holding zombies. Skips init and own process tree.
`install-cron`	Adds a cron entry that checks every 30 minutes and logs alerts to `~/.zombie-alerts.log` when count exceeds threshold
`uninstall-cron`	Removes the cron entry
`status`	Shows threshold, cron state, current zombie count, and recent alerts

Configuration

Threshold: Set ZOMBIE_THRESHOLD=N (default: 5) to control when alerts fire
Alert log: Written to ~/.zombie-alerts.log

How It Works

Zombie processes are children that have exited but whose parent hasn't called wait() to collect the exit status. They consume no CPU/memory but occupy PID table entries. The fix is to kill the parent process — init then adopts and reaps the orphaned zombies.

Common causes on this VPS:
- Codex CLI doesn't properly reap bash subprocesses during long sessions
- Stale agent sessions (Claude/Codex) running for days accumulate zombies

Workflow

Run scan to see current state
Run kill to clean up (safe — skips init and own process tree)
Run install-cron for ongoing monitoring
Check status or ~/.zombie-alerts.log periodically

# Supported AI Coding Agents

This skill is compatible with the SKILL.md standard and works with all major AI coding agents:

⚡ Amp 🚀 Antigravity 🤖 Claude Code 🦀 Clawdbot 📝 Codex ▶️ Cursor 🤖 Droid 💎 Gemini CLI 🐙 GitHub Copilot 🪿 Goose 📊 Kilo Code 🔧 Kiro CLI 💻 OpenCode 🦘 Roo Code 🌲 Trae 🏄 Windsurf

Learn more about the SKILL.md standard and how to use these skills with your preferred AI coding agent.