git:20260913.4cedcda to v3.0.0

+ ---

+ name: cron-scheduler-expert

+ description: "Expert guide for scheduled tasks, cron jobs, recurring background work (Vercel Cron, Cloudflare Workers Cron, Inngest, node-cron), and distributed scheduling / Panduan ahli untuk tugas terjadwal, cron job, pekerjaan latar belakang berulang, dan penjadwalan terdistribusi."

+ author: "Roedy Rustam"

+ version: "3.0.0"

+ ---

+

+ # Cron & Scheduler Expert (2026 Edition)

+

+ [English](#english) | [Bahasa Indonesia](#bahasa-indonesia)

+

+ ---

+

+ <a name="english"></a>

+ ## English

+

+ ### Orchestration & Integration

+ Connects and orchestrates with relevant domain skills like `brainstorming`, `zero-to-prod-orchestrator`, and `session-memory-manager` to ensure cohesive execution.

+

+ ### Description

+ Production-grade guide for implementing scheduled tasks, cron jobs, and recurring background work in modern web applications. Covers **Vercel Cron Jobs**, **Cloudflare Workers Cron Triggers**, **Inngest scheduled functions**, **node-cron**, **BullMQ repeatable jobs**, **distributed cron locking** (Redis-based), **timezone-aware scheduling**, and common use cases (cleanup jobs, report generation, health checks, subscription renewals).

+

+ ### Trigger Conditions

+ Activate this skill when:

+ - Setting up scheduled/recurring tasks (daily reports, cleanup, health checks).

+ - Configuring Vercel Cron Jobs or Cloudflare Workers Cron Triggers.

+ - Implementing subscription renewal checks or billing cycle jobs.

+ - Building data aggregation or ETL pipelines on a schedule.

+ - Needing distributed cron locking to prevent duplicate execution.

+ - Scheduling email digests or notification batches.

+

+ ---

+

+ ### Platform Selection Guide

+

+ | Platform | Best For | Max Frequency | Invocation Model |

+ |---|---|---|---|

+ | **Vercel Cron** | Vercel-hosted Next.js apps | 1/min (Pro), 1/day (Hobby) | HTTP endpoint trigger |

+ | **Cloudflare Workers Cron** | Edge-first apps | 1/min | Worker script trigger |

+ | **Inngest** | Complex workflows, fan-out | Any (event-driven) | Serverless function |

+ | **BullMQ Repeatable** | Self-hosted, Redis-backed | Any | Worker process |

+ | **node-cron** | Simple Node.js servers | Any | In-process |

+ | **Trigger.dev v3** | Durable scheduled tasks | Any | Serverless function |

+

+ **Recommendation**: Use **Vercel Cron** for Next.js apps on Vercel. Use **Inngest** for complex multi-step scheduled workflows. Use **BullMQ repeatable jobs** for self-hosted environments.

+

+ ---

+

+ ### 1. Vercel Cron Jobs

+

+ ```json

+ // vercel.json

+ {

+ "crons": [

+ {

+ "path": "/api/cron/daily-cleanup",

+ "schedule": "0 3 * * *"

+ },

+ {

+ "path": "/api/cron/hourly-health-check",

+ "schedule": "0 * * * *"

+ },

+ {

+ "path": "/api/cron/weekly-report",

+ "schedule": "0 9 * * 1"

+ }

+ ]

+ }

+ ```

+

+ ```typescript

+ // app/api/cron/daily-cleanup/route.ts

+ import { NextResponse } from 'next/server';

+

+ export async function GET(request: Request) {

+ // Verify the request is from Vercel Cron (not public)

+ const authHeader = request.headers.get('authorization');

+ if (authHeader !== `Bearer ${process.env.CRON_SECRET}`) {

+ return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

+ }

+

+ try {

+ // Cleanup expired sessions

+ const deletedSessions = await db.delete(sessions)

+ .where(lt(sessions.expiresAt, new Date()));

+

+ // Cleanup orphaned uploads (older than 24h, not linked to any record)

+ const deletedUploads = await db.delete(uploads)

+ .where(and(

+ isNull(uploads.linkedRecordId),

+ lt(uploads.createdAt, new Date(Date.now() - 86400000)),

+ ));

+

+ return NextResponse.json({

+ ok: true,

+ cleaned: { sessions: deletedSessions.rowCount, uploads: deletedUploads.rowCount },

+ });

+ } catch (error) {

+ console.error('Daily cleanup failed:', error);

+ return NextResponse.json({ ok: false, error: 'Cleanup failed' }, { status: 500 });

+ }

+ }

+

+ export const runtime = 'nodejs';

+ export const maxDuration = 60; // Allow up to 60s for cleanup

+ ```

+

+ ---

+

+ ### 2. Inngest Scheduled Functions

+

+ ```typescript

+ // inngest/functions/weekly-report.ts

+ import { inngest } from '@/lib/inngest';

+

+ export const weeklyReportJob = inngest.createFunction(

+ {

+ id: 'weekly-usage-report',

+ name: 'Generate Weekly Usage Report',

+ },

+ { cron: 'TZ=Asia/Jakarta 0 9 * * 1' }, // Every Monday 9 AM WIB

+ async ({ step }) => {

+ // Step 1: Gather data

+ const metrics = await step.run('gather-metrics', async () => {

+ return await db.query.usageMetrics.findMany({

+ where: gte(usageMetrics.createdAt, subDays(new Date(), 7)),

+ });

+ });

+

+ // Step 2: Generate report

+ const report = await step.run('generate-report', async () => {

+ return generateWeeklyReport(metrics);

+ });

+

+ // Step 3: Send to admins

+ await step.run('send-report', async () => {

+ const admins = await db.query.users.findMany({

+ where: eq(users.role, 'admin'),

+ });

+ for (const admin of admins) {

+ await emailQueue.add('weekly-report', { to: admin.email, report });

+ }

+ });

+

+ return { sent: true, reportId: report.id };

+ },

+ );

+ ```

+

+ ---

+

+ ### 3. BullMQ Repeatable Jobs

+

+ ```typescript

+ // queues/scheduled-jobs.ts

+ import { Queue, Worker } from 'bullmq';

+

+ const scheduledQueue = new Queue('scheduled', {

+ connection: { host: process.env.REDIS_HOST },

+ });

+

+ // Add repeatable jobs on startup

+ export async function registerScheduledJobs() {

+ // Daily cleanup at 3 AM

+ await scheduledQueue.add('daily-cleanup', {}, {

+ repeat: { pattern: '0 3 * * *', tz: 'Asia/Jakarta' },

+ jobId: 'daily-cleanup', // Prevent duplicates on restart

+ });

+

+ // Every 5 minutes: health check

+ await scheduledQueue.add('health-check', {}, {

+ repeat: { every: 5 * 60 * 1000 }, // 5 minutes in ms

+ jobId: 'health-check',

+ });

+

+ // Monthly: subscription renewal check (1st of each month at midnight)

+ await scheduledQueue.add('subscription-renewal', {}, {

+ repeat: { pattern: '0 0 1 * *', tz: 'Asia/Jakarta' },

+ jobId: 'subscription-renewal',

+ });

+ }

+

+ // Worker

+ const worker = new Worker('scheduled', async (job) => {

+ switch (job.name) {

+ case 'daily-cleanup':

+ await performDailyCleanup();

+ break;

+ case 'health-check':

+ await performHealthCheck();

+ break;

+ case 'subscription-renewal':

+ await checkSubscriptionRenewals();

+ break;

+ }

+ }, { connection: { host: process.env.REDIS_HOST } });

+ ```

+

+ ---

+

+ ### 4. Distributed Cron Locking (Redis)

+

+ ```typescript

+ // lib/cron-lock.ts

+ import { Redis } from 'ioredis';

+

+ const redis = new Redis(process.env.REDIS_URL!);

+

+ /**

+ * Acquire a distributed lock to prevent duplicate cron execution

+ * across multiple server instances.

+ */

+ export async function acquireCronLock(

+ jobName: string,

+ ttlSeconds: number = 300,

+ ): Promise<boolean> {

+ const lockKey = `cron-lock:${jobName}`;

+ // SET NX (only if not exists) with TTL

+ const result = await redis.set(lockKey, Date.now().toString(), 'EX', ttlSeconds, 'NX');

+ return result === 'OK';

+ }

+

+ export async function releaseCronLock(jobName: string): Promise<void> {

+ await redis.del(`cron-lock:${jobName}`);

+ }

+

+ // Usage in cron handler

+ export async function GET(request: Request) {

+ const locked = await acquireCronLock('daily-cleanup', 300);

+ if (!locked) {

+ return Response.json({ skipped: true, reason: 'Already running on another instance' });

+ }

+

+ try {

+ await performDailyCleanup();

+ return Response.json({ ok: true });

+ } finally {

+ await releaseCronLock('daily-cleanup');

+ }

+ }

+ ```

+

+ ---

+

+ ### Common Cron Patterns

+

+ | Schedule | Cron Expression | Description |

+ |---|---|---|

+ | Every minute | `* * * * *` | Health checks, queue monitoring |

+ | Every 5 minutes | `*/5 * * * *` | Cache warming, metric aggregation |

+ | Every hour | `0 * * * *` | Data sync, report generation |

+ | Daily at 3 AM | `0 3 * * *` | Cleanup, backups |

+ | Weekly Monday 9 AM | `0 9 * * 1` | Weekly reports |

+ | Monthly 1st at midnight | `0 0 1 * *` | Billing cycles, subscription renewals |

+ | Weekdays at 8 AM | `0 8 * * 1-5` | Business notifications |

+

+ ---

+

+ ### Common Pitfalls to Avoid

+

+ | Anti-Pattern | Problem | Correct Approach |

+ |---|---|---|

+ | No distributed locking | Duplicate execution across instances | Use Redis-based NX lock |

+ | Long-running cron without timeout | Resource exhaustion, overlapping runs | Set `maxDuration` and use lock TTL |

+ | No monitoring of cron failures | Silent failures go unnoticed | Log results, alert on failures |

+ | Hardcoded timezone | Jobs run at wrong time after DST | Always use explicit `tz` parameter |

+ | Cron job does too much work | Timeout, partial completion | Break into smaller steps (Inngest/Temporal) |

+

+ ---

+

+ ### Integration with Other Skills

+

+ - `async-queue-temporal-expert` — BullMQ repeatable jobs, Inngest scheduled functions

+ - `cloud-hosting-expert` — Vercel Cron, Cloudflare Workers Cron configuration

+ - `saas-billing` — Subscription renewal checks, billing cycle jobs

+ - `email-notification-expert` — Scheduled email digests, daily summaries

+ - `data-telemetry-expert` — Scheduled metric aggregation and reporting

+ - `logging-error-tracking-expert` — Cron job failure monitoring

+

+ ---

+

+ <a name="bahasa-indonesia"></a>

+ ## Bahasa Indonesia

+

+ ### Integrasi Orkestrasi

+ Terhubung dan mengorkestrasi skill domain yang relevan seperti `brainstorming`, `zero-to-prod-orchestrator`, dan `session-memory-manager` untuk memastikan eksekusi yang kohesif.

+

+ ### Deskripsi

+ Panduan tingkat produksi untuk mengimplementasikan tugas terjadwal, cron job, dan pekerjaan latar belakang berulang di aplikasi web modern. Mencakup **Vercel Cron Jobs**, **Cloudflare Workers Cron Triggers**, **Inngest scheduled functions**, **node-cron**, **BullMQ repeatable jobs**, **distributed cron locking** (berbasis Redis), **penjadwalan sadar zona waktu**, dan kasus penggunaan umum (pembersihan data, pembuatan laporan, health check, perpanjangan langganan).

+

+ ### Kondisi Pemicu

+ Aktifkan skill ini ketika:

+ - Menyiapkan tugas terjadwal/berulang (laporan harian, pembersihan, health check).

+ - Mengonfigurasi Vercel Cron Jobs atau Cloudflare Workers Cron Triggers.

+ - Mengimplementasikan pemeriksaan perpanjangan langganan atau siklus billing.

+ - Membangun pipeline agregasi data atau ETL pada jadwal tertentu.

+ - Membutuhkan penguncian cron terdistribusi untuk mencegah eksekusi duplikat.

+

+ ### Integrasi dengan Skill Lain

+

+ - `async-queue-temporal-expert` — BullMQ repeatable jobs, Inngest scheduled functions

+ - `cloud-hosting-expert` — Konfigurasi Vercel Cron, Cloudflare Workers Cron

+ - `saas-billing` — Pemeriksaan perpanjangan langganan, siklus billing

+ - `email-notification-expert` — Digest email terjadwal, ringkasan harian