trinhhaox/ag-kit/caching-strategies

Browser Cache (fastest, per-user)
  → CDN / Edge Cache (regional, shared)
    → Reverse Proxy (Nginx, Varnish)
      → Application Cache (Redis, in-memory)
        → Database Cache (query cache, materialized views)

async function getData(key: string) {
  let data = await redis.get(key);
  if (!data) {
    data = await db.query(key);
    await redis.set(key, data, { EX: 3600 });
  }
  return data;
}

async function saveData(key: string, value: any) {
  await db.save(key, value);
  await redis.set(key, value, { EX: 3600 });
}

// Return stale data immediately, refresh in background
Cache-Control: max-age=60, stale-while-revalidate=300

{service}:{entity}:{id}:{field}
# e.g., app:user:123:profile

// On data change, publish invalidation event
await redis.del(`app:user:${userId}:profile`);
await redis.publish('cache:invalidate', JSON.stringify({ key, reason }));

// Tag cache entries, invalidate by tag
await redis.sadd('tag:user:123', 'app:user:123:profile', 'app:user:123:orders');
// Invalidate all entries for user 123
const keys = await redis.smembers('tag:user:123');
await redis.del(...keys);

const version = await redis.incr('version:products');
const key = `products:v${version}:list`;

// app/products/[id]/page.tsx
export const revalidate = 3600; // Revalidate every hour
// On-demand revalidation
// app/api/revalidate/route.ts
import { revalidatePath, revalidateTag } from 'next/cache';
export async function POST(req: Request) {
  revalidateTag('products');
  return Response.json({ revalidated: true });
}

// Cache indefinitely (default in Next.js)
fetch(url, { cache: 'force-cache' });
// Revalidate every 60 seconds
fetch(url, { next: { revalidate: 60 } });
// Never cache
fetch(url, { cache: 'no-store' });
// Tag-based
fetch(url, { next: { tags: ['products'] } });