Caching — Animate | AI Wisdom

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🎞 ANIMATE · Mode 3 of 5 · +100 XP— Cache-Aside Pattern
🔍Cache Check
⚡Cache Hit
📭Cache Miss
💾Populate
🎯 Next: Test →
Step 1 / 4
Speed
Check Redis first
Every read checks Redis before hitting the database💡 Analogy
Like checking your memory before looking something up in a book.
First call to Redis: get('user:123'). If found, return immediately.
Console Output
> redis.get("user:123")
> Checking cache...
●cache-aside.ts
Check Redis firstL10–11
1import { Redis } from 'ioredis';
2import { db } from './db';
3 
4const redis = new Redis();
5const TTL = 300; // 5 minutes
6 
7export async function getUser(userId: string) {
8  const cacheKey = `user:${userId}`;
9 
10  // 1. Check cache
11  const cached = await redis.get(cacheKey);
12  if (cached) {
13    return JSON.parse(cached);          // Cache HIT
14  }
15 
16  // 2. Cache MISS — load from DB
17  const user = await db.query(
18    'SELECT * FROM users WHERE id = $1',
19    [userId]
20  );
21 
22  // 3. Populate cache
23  await redis.setex(cacheKey, TTL, JSON.stringify(user));
24 
25  return user;
26}
27 
28export async function updateUser(userId: string, data: object) {
29  await db.query('UPDATE users SET ... WHERE id = $1', [userId]);
30  await redis.del(`user:${userId}`);     // Invalidate cache
31}
31 lines
Timeline — 4 Steps
Check Redis first
Every read checks Redis before hitting the database💡 Analogy
Like checking your memory before looking something up in a book.
First call to Redis: get('user:123'). If found, return immediately.
Console Output
> redis.get("user:123")
> Checking cache...

Every read checks Redis before hitting the database

Every read checks Redis before hitting the database

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Every read checks Redis before hitting the database

Every read checks Redis before hitting the database

Was this page helpful?

Discussion