Cache Warm-Up Cron Job

Hit your most-visited pages every 10 minutes so the CDN edge cache stays warm and real users get instant responses.

Why warm the cache?

CDN caches and server-side caches expire after a TTL (time-to-live). When a cache entry expires, the next visitor to that page triggers a cache miss — the server has to regenerate the response, which can take 500ms–5s depending on your stack. If traffic is low, popular pages can go cold between visits.

A cache warm-up job pre-fetches your most important URLs on a regular interval, ensuring the cache is always populated before real users arrive.

Bash warm-up script

#!/bin/bash
URLS=(
  "https://yoshi.tools/"
  "https://yoshi.tools/guides/morning-brief.html"
  "https://yoshi.tools/guides/database-backup.html"
  "https://yoshi.tools/guides/weekly-report.html"
)

for url in "${URLS[@]}"; do
  STATUS=$(curl -s -o /dev/null -w "%{http_code}" "$url")
  echo "$(date -u) $STATUS $url"
done

Platform snippets

*/10 * * * *    /usr/local/bin/cache-warmup.sh >> /var/log/cache-warmup.log 2>&1

on:
  schedule:
    - cron: '*/10 * * * *'

jobs:
  warmup:
    runs-on: ubuntu-latest
    steps:
      - name: Warm cache
        run: |
          for url in \
            "https://yoshi.tools/" \
            "https://yoshi.tools/guides/morning-brief.html"; do
            curl -s -o /dev/null "$url"
            echo "Warmed: $url"
          done

# Note: EventBridge minimum interval is 1 minute
cron(*/10 * * * ? *)

{
  "crons": [
    {
      "path": "/api/warmup",
      "schedule": "*/10 * * * *"
    }
  ]
}

Vercel / Next.js API route

// app/api/warmup/route.ts
export async function GET() {
  const urls = [
    process.env.NEXT_PUBLIC_URL + '/',
    process.env.NEXT_PUBLIC_URL + '/guides/morning-brief.html',
  ]
  await Promise.all(urls.map(url => fetch(url)))
  return Response.json({ ok: true, warmed: urls.length })
}

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