Monitor nighttime system health with Google Sheets, GPT-4o-mini and Gmail

This template automates overnight system health monitoring for DevOps and IT operations teams. It checks your internal services and APIs on a schedule, logs all results to Google Sheets, and sends AI-generated alert emails when something goes wrong.

Who this is for System administrators, DevOps engineers, and IT operations teams who need lightweight, automated overnight monitoring — without setting up a full-scale monitoring platform.

What's included A single workflow that handles the full monitoring loop:

1. Read Monitor Targets — Reads active URLs from Google Sheets. Add or disable targets anytime without touching the workflow. 2. Health Check — Sends HTTP GET requests with a 3-second timeout to each target. 3. Response Time Tracking — Measures and logs response time in milliseconds for every check. 4. Full Result Logging — Appends every check result (OK and ERROR) to a Google Sheets log with timestamp, status, status code, response time, error message, and alert status. 5. AI-Generated Alert — On failure, GPT-4o-mini generates a structured Japanese alert message with situation summary, urgency level, first steps to check, and escalation guidance. 6. Gmail Alert — Sends the alert email to a configured address with a clear subject line. 7. Alert Status Tracking — Updates the log to mark when an alert has been sent.

Key features - Manage all monitoring targets in Google Sheets — no workflow edits needed to add or remove URLs - Monitors both HTTP errors (503 etc.) and connection failures (timeout, ECONNREFUSED) - Logs every check result for uptime analysis and audit purposes - AI alert in Japanese with actionable first-response guidance - Configurable schedule via Cron expression (default: every 10 min, weekdays 1:00–4:59 AM) - Timezone follows your n8n instance setting — no hardcoded timezone

Prerequisites - Google Sheets (copy link provided in the workflow) - Gmail account connected to n8n - OpenAI API key

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このテンプレートは、DevOpsおよびIT運用チーム向けに夜間のシステム死活監視を自動化します。スケジュールに従って社内サービスやAPIをチェックし、全結果をGoogle Sheetsに記録し、障害検知時にはAIが生成したアラートメールを送信します。