Message Queues — Animate | AI Wisdom

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🎞 ANIMATE · Mode 3 of 5 · +100 XP— Message Queue (Bull/Redis)
📋Enqueue
⚙️Worker
🔄Process
✅Retry
🎯 Next: Test →
Step 1 / 4
Speed
Enqueue job
Producer adds email jobs to Bull queue in Redis💡 Analogy
Drop mail in the outbox — don't drive to the post office yourself.
The API handler adds a job to the queue instead of sending email immediately. Returns instantly.
Console Output
> queueEmail("alice@co.com", "welcome", {...})
> job added to Redis: id=1, status=waiting
> HTTP response returned immediately
●queue.ts
Enqueue jobL6–11
1import Bull from 'bull';
2 
3const emailQueue = new Bull('emails', { redis: { host: 'localhost' } });
4 
5// Producer: add jobs to queue
6async function queueEmail(to: string, template: string, data: object) {
7  await emailQueue.add({ to, template, data }, {
8    attempts: 3,          // Retry up to 3 times
9    backoff: { type: 'exponential', delay: 2000 },
10    removeOnComplete: 100, // Keep last 100 completed
11  });
12  console.log(`Queued email to ${to}`);
13}
14 
15// Consumer: process jobs
16emailQueue.process(5, async (job) => {  // 5 concurrent workers
17  const { to, template, data } = job.data;
18  console.log(`Processing: email to ${to}`);
19  await sendEmail(to, template, data);
20  return { sent: true, timestamp: Date.now() };
21});
22 
23// Event listeners
24emailQueue.on('completed', (job) => console.log(`✅ Job ${job.id} done`));
25emailQueue.on('failed', (job, err) => console.log(`❌ Job ${job.id}: ${err}`));
26 
27// Send 1000 welcome emails
28for (const user of newUsers) {
29  await queueEmail(user.email, 'welcome', { name: user.name });
30}
30 lines
Timeline — 4 Steps
Enqueue job
Producer adds email jobs to Bull queue in Redis💡 Analogy
Drop mail in the outbox — don't drive to the post office yourself.
The API handler adds a job to the queue instead of sending email immediately. Returns instantly.
Console Output
> queueEmail("alice@co.com", "welcome", {...})
> job added to Redis: id=1, status=waiting
> HTTP response returned immediately

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Discussion

Producer adds email jobs to Bull queue in Redis

💡 Analogy

Drop mail in the outbox — don't drive to the post office yourself.

The API handler adds a job to the queue instead of sending email immediately. Returns instantly.

Console Output

> queueEmail("alice@co.com", "welcome", {...})
> job added to Redis: id=1, status=waiting
> HTTP response returned immediately

Producer adds email jobs to Bull queue in Redis

💡 Analogy

Drop mail in the outbox — don't drive to the post office yourself.

The API handler adds a job to the queue instead of sending email immediately. Returns instantly.

Console Output

> queueEmail("alice@co.com", "welcome", {...})
> job added to Redis: id=1, status=waiting
> HTTP response returned immediately