damjan_savicandClaude Opus 4.5
43484c5023
- Add 100 blog posts covering AI, development, and tech topics - Add .env.example for environment configuration - Add accessibility and lighthouse audit scripts - Remove obsolete SEO reports and temporary files - Remove dev-dist build artifacts and backup files - Remove unused portrait images (moved/consolidated elsewhere) - Update contact form and component improvements Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
515 lines
13 KiB
Markdown
515 lines
13 KiB
Markdown
# Cron Jobs & Task Scheduling in Node.js
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**Meta-Description:** Task Scheduling für Node.js. Cron Syntax, node-cron, BullMQ Repeatable Jobs und Serverless Scheduling.
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**Keywords:** Cron Jobs, Task Scheduling, Node.js, node-cron, BullMQ, Scheduled Tasks, Background Jobs
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---
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## Einführung
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Automatisierte Aufgaben sind das Rückgrat jeder Anwendung: **Backups, Reports, Cleanup, Sync-Jobs**. Mit Cron Jobs laufen sie zuverlässig zu definierten Zeiten – ohne manuellen Eingriff.
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---
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## Cron Syntax
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```
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┌─────────────────────────────────────────────────────────────┐
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│ CRON EXPRESSION │
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├─────────────────────────────────────────────────────────────┤
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│ │
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│ ┌───────────── Minute (0-59) │
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│ │ ┌───────────── Stunde (0-23) │
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│ │ │ ┌───────────── Tag des Monats (1-31) │
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│ │ │ │ ┌───────────── Monat (1-12) │
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│ │ │ │ │ ┌───────────── Wochentag (0-7, 0 und 7 = Sonntag)│
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│ │ │ │ │ │ │
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│ * * * * * │
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│ │
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│ Beispiele: │
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│ ├── * * * * * → Jede Minute │
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│ ├── 0 * * * * → Jede volle Stunde │
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│ ├── 0 0 * * * → Täglich um Mitternacht │
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│ ├── 0 8 * * 1-5 → Mo-Fr um 8:00 │
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│ ├── 0 0 1 * * → Am 1. jeden Monats │
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│ ├── */15 * * * * → Alle 15 Minuten │
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│ └── 0 9,18 * * * → Um 9:00 und 18:00 │
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│ │
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└─────────────────────────────────────────────────────────────┘
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```
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---
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## node-cron Setup
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```bash
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npm install node-cron
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npm install -D @types/node-cron
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```
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```typescript
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import cron from 'node-cron';
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// Basic Scheduled Task
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cron.schedule('* * * * *', () => {
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console.log('Runs every minute');
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});
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// Mit Timezone
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cron.schedule('0 8 * * *', () => {
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console.log('Daily at 8:00 AM Berlin time');
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}, {
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timezone: 'Europe/Berlin'
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});
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// Task mit Start/Stop
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const task = cron.schedule('*/5 * * * *', () => {
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console.log('Every 5 minutes');
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}, {
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scheduled: false // Nicht automatisch starten
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});
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// Manuell starten/stoppen
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task.start();
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// task.stop();
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// Validation
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const isValid = cron.validate('* * * * *'); // true
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```
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---
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## Praktische Scheduler-Klasse
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```typescript
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import cron, { ScheduledTask } from 'node-cron';
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interface Job {
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name: string;
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schedule: string;
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handler: () => Promise<void>;
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enabled: boolean;
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timezone?: string;
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}
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class TaskScheduler {
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private tasks: Map<string, ScheduledTask> = new Map();
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private jobs: Map<string, Job> = new Map();
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register(job: Job) {
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this.jobs.set(job.name, job);
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if (job.enabled) {
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this.startJob(job.name);
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}
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}
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startJob(name: string) {
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const job = this.jobs.get(name);
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if (!job) throw new Error(`Job ${name} not found`);
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if (this.tasks.has(name)) {
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console.log(`Job ${name} already running`);
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return;
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}
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const task = cron.schedule(job.schedule, async () => {
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const startTime = Date.now();
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console.log(`[${name}] Starting...`);
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try {
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await job.handler();
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console.log(`[${name}] Completed in ${Date.now() - startTime}ms`);
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} catch (error) {
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console.error(`[${name}] Failed:`, error);
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// Alert senden
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}
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}, {
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timezone: job.timezone || 'Europe/Berlin'
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});
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this.tasks.set(name, task);
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console.log(`[${name}] Scheduled: ${job.schedule}`);
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}
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stopJob(name: string) {
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const task = this.tasks.get(name);
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if (task) {
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task.stop();
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this.tasks.delete(name);
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console.log(`[${name}] Stopped`);
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}
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}
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stopAll() {
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for (const [name, task] of this.tasks) {
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task.stop();
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console.log(`[${name}] Stopped`);
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}
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this.tasks.clear();
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}
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getStatus(): Array<{ name: string; schedule: string; running: boolean }> {
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return Array.from(this.jobs.values()).map(job => ({
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name: job.name,
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schedule: job.schedule,
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running: this.tasks.has(job.name)
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}));
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}
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}
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// Verwendung
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const scheduler = new TaskScheduler();
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scheduler.register({
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name: 'daily-backup',
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schedule: '0 2 * * *',
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handler: async () => {
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await performDatabaseBackup();
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},
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enabled: true
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});
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scheduler.register({
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name: 'hourly-sync',
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schedule: '0 * * * *',
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handler: async () => {
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await syncExternalData();
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},
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enabled: true
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});
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scheduler.register({
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name: 'weekly-report',
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schedule: '0 9 * * 1', // Montag 9:00
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handler: async () => {
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await generateWeeklyReport();
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await sendReportEmail();
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},
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enabled: true
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});
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// Graceful Shutdown
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process.on('SIGTERM', () => {
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scheduler.stopAll();
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process.exit(0);
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});
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```
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---
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## BullMQ Repeatable Jobs
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```typescript
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import { Queue, Worker } from 'bullmq';
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import IORedis from 'ioredis';
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const connection = new IORedis(process.env.REDIS_URL!);
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// Queue für Scheduled Jobs
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const scheduledQueue = new Queue('scheduled-tasks', { connection });
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// Repeatable Jobs registrieren
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async function setupScheduledJobs() {
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// Täglich um 2:00 UTC
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await scheduledQueue.add('database-backup', {}, {
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repeat: {
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pattern: '0 2 * * *',
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tz: 'Europe/Berlin'
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},
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jobId: 'daily-backup' // Verhindert Duplikate
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});
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// Alle 5 Minuten
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await scheduledQueue.add('health-check', {}, {
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repeat: {
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every: 5 * 60 * 1000 // Millisekunden
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},
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jobId: 'health-check'
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});
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// Wöchentlich Montag 9:00
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await scheduledQueue.add('weekly-report', { type: 'weekly' }, {
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repeat: {
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pattern: '0 9 * * 1',
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tz: 'Europe/Berlin'
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},
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jobId: 'weekly-report'
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});
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// Monatlich am 1.
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await scheduledQueue.add('monthly-cleanup', {}, {
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repeat: {
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pattern: '0 3 1 * *',
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tz: 'Europe/Berlin'
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},
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jobId: 'monthly-cleanup'
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});
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}
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// Worker für Scheduled Jobs
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const worker = new Worker('scheduled-tasks', async (job) => {
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console.log(`Processing ${job.name}`);
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switch (job.name) {
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case 'database-backup':
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await performDatabaseBackup();
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break;
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case 'health-check':
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await runHealthChecks();
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break;
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case 'weekly-report':
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await generateAndSendReport('weekly');
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break;
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case 'monthly-cleanup':
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await cleanupOldData();
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break;
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default:
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console.warn(`Unknown job: ${job.name}`);
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}
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return { completed: true };
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}, { connection });
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worker.on('completed', (job, result) => {
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console.log(`Job ${job.name} completed`);
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});
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worker.on('failed', (job, error) => {
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console.error(`Job ${job?.name} failed:`, error);
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// Alert senden
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});
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// Repeatable Jobs verwalten
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async function listScheduledJobs() {
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const jobs = await scheduledQueue.getRepeatableJobs();
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return jobs.map(job => ({
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name: job.name,
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pattern: job.pattern || `every ${job.every}ms`,
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next: new Date(job.next).toISOString()
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}));
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}
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async function removeScheduledJob(jobId: string) {
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const jobs = await scheduledQueue.getRepeatableJobs();
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const job = jobs.find(j => j.id === jobId);
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if (job) {
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await scheduledQueue.removeRepeatableByKey(job.key);
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console.log(`Removed job: ${jobId}`);
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}
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}
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```
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---
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## Serverless Cron (Vercel/AWS)
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```typescript
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// Vercel Cron Jobs (vercel.json)
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{
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"crons": [
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{
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"path": "/api/cron/daily-backup",
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"schedule": "0 2 * * *"
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},
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{
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"path": "/api/cron/hourly-sync",
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"schedule": "0 * * * *"
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}
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]
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}
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// app/api/cron/daily-backup/route.ts
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import { NextRequest, NextResponse } from 'next/server';
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export const runtime = 'edge';
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export const maxDuration = 60; // 60 Sekunden max
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export async function GET(request: NextRequest) {
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// Verify Cron Secret (Security)
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const authHeader = request.headers.get('authorization');
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if (authHeader !== `Bearer ${process.env.CRON_SECRET}`) {
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return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
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}
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try {
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await performBackup();
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return NextResponse.json({
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success: true,
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timestamp: new Date().toISOString()
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});
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} catch (error) {
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console.error('Backup failed:', error);
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return NextResponse.json({
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success: false,
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error: (error as Error).message
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}, { status: 500 });
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}
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}
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// AWS EventBridge + Lambda
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// serverless.yml
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// functions:
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// dailyBackup:
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// handler: src/handlers/backup.handler
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// events:
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// - schedule: cron(0 2 * * ? *)
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```
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---
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## Job Locking (Prevent Duplicates)
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```typescript
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import { Redis } from 'ioredis';
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const redis = new Redis(process.env.REDIS_URL!);
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async function withJobLock<T>(
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jobName: string,
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ttlSeconds: number,
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handler: () => Promise<T>
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): Promise<T | null> {
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const lockKey = `job-lock:${jobName}`;
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// Versuche Lock zu erwerben
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const acquired = await redis.set(lockKey, Date.now().toString(), 'EX', ttlSeconds, 'NX');
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if (!acquired) {
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console.log(`Job ${jobName} already running, skipping`);
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return null;
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}
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try {
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return await handler();
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} finally {
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// Lock freigeben
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await redis.del(lockKey);
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}
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}
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// Verwendung
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cron.schedule('*/5 * * * *', async () => {
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await withJobLock('sync-products', 300, async () => {
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// Dieser Code läuft garantiert nur einmal
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await syncProducts();
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});
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});
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```
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---
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## Monitoring & Alerting
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```typescript
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interface JobExecution {
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jobName: string;
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startedAt: Date;
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completedAt?: Date;
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status: 'running' | 'completed' | 'failed';
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error?: string;
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duration?: number;
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}
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class JobMonitor {
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private executions: Map<string, JobExecution> = new Map();
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async trackExecution<T>(
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jobName: string,
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handler: () => Promise<T>
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): Promise<T> {
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const executionId = `${jobName}-${Date.now()}`;
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this.executions.set(executionId, {
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jobName,
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startedAt: new Date(),
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status: 'running'
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});
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try {
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const result = await handler();
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const execution = this.executions.get(executionId)!;
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execution.completedAt = new Date();
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execution.status = 'completed';
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execution.duration = execution.completedAt.getTime() - execution.startedAt.getTime();
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// Log to database
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await this.saveExecution(execution);
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return result;
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} catch (error) {
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const execution = this.executions.get(executionId)!;
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execution.completedAt = new Date();
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execution.status = 'failed';
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execution.error = (error as Error).message;
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execution.duration = execution.completedAt.getTime() - execution.startedAt.getTime();
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await this.saveExecution(execution);
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await this.sendAlert(execution);
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throw error;
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} finally {
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// Cleanup alte Executions
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setTimeout(() => this.executions.delete(executionId), 60000);
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}
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}
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private async saveExecution(execution: JobExecution) {
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await db.jobExecution.create({ data: execution });
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}
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private async sendAlert(execution: JobExecution) {
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// Slack, Email, PagerDuty, etc.
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await slack.send({
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text: `❌ Job Failed: ${execution.jobName}`,
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attachments: [{
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color: 'danger',
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fields: [
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{ title: 'Error', value: execution.error || 'Unknown' },
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{ title: 'Duration', value: `${execution.duration}ms` }
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]
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}]
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});
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}
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}
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```
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---
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## Fazit
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Task Scheduling in Node.js:
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1. **node-cron**: Einfach für Single-Server
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2. **BullMQ**: Distributed, Reliable, Scalable
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3. **Serverless Cron**: Vercel, AWS EventBridge
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4. **Job Locking**: Verhindert Duplikate
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Zuverlässige Automation für jede Anwendung.
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---
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## Bildprompts
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1. "Clock with automated tasks running at specific times, scheduling concept"
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2. "Multiple servers coordinating scheduled jobs, distributed cron"
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3. "Calendar with recurring events and checkmarks, automated workflow"
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---
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## Quellen
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- [node-cron Documentation](https://www.npmjs.com/package/node-cron)
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- [BullMQ Repeatable Jobs](https://docs.bullmq.io/guide/jobs/repeatable)
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- [Vercel Cron Jobs](https://vercel.com/docs/cron-jobs)
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- [Cron Expression Generator](https://crontab.guru/)
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