Apa bedane antara runtime Edge lan Node.js?

Question

IT Interview Practice · Accepted Answer

Next.js bisa njalanake code server ing rong runtime. **Runtime Node.js** (default) iku lingkungan Node lengkap; **runtime Edge** iku lingkungan ringan berbasis V8 sing nanggo ing lokasi edge sing disebarake sacara global cedhak karo pangguna.

## Milih runtime

```ts
// per route handler / page
export const runtime = "edge";   // or "nodejs" (the default)
```

## Pamilihe

```text
                  Node.js runtime         Edge runtime
────────────────────────────────────────────────────────────────
APIs              full Node (fs, crypto,  Web APIs only (fetch,
                  Buffer, native modules) Request/Response) — limited
npm packages      all                     only those without Node APIs
Cold start        slower, heavier         near-zero, lightweight
Location          regional (one region)   global (near the user)
Latency to user   higher if far away      very low (geo-distributed)
Execution limits  longer, more memory     short CPU time, less memory
Database          direct TCP connections  HTTP-based DBs only (no raw TCP)
```

## Kapan nggunake Edge

```text
✓ Middleware (auth checks, redirects, geo-routing) — must be fast & global
✓ Simple, latency-sensitive endpoints (personalization, A/B, feature flags)
✓ Reading geolocation/headers to tailor responses
```

Edge bincik kanggo **logika ringan sing bisa entuk manfaat saka cedhake pangguna** lan saka cold start sing instant.

## Kapan nggunake Node.js

```text
✓ Direct database connections (Prisma over TCP, etc.)
✓ Heavy computation, large dependencies, native modules
✓ Anything using Node-specific APIs (fs, crypto.randomBytes via Node, Buffer)
```

## Conto kendala nyata

```ts
export const runtime = "edge";
import fs from "fs";           // ❌ not available on Edge — build/runtime error
import { PrismaClient } from "@prisma/client"; // ⚠️ needs HTTP/data-proxy on Edge
```

Kabiasane perpustakaan populer (kalebu ORM sing mbukak raw DB socket) ora bisa berjalan ing Edge tanpa adapter berbasis HTTP — iku kendhala umum.

## Mengapa penting

Nilih runtime iku kaputusan aritektur nyata: **Edge** kanggo logika cepet, global, ringan (utama middleware) karo cold start minimal, **Node.js** kanggo akses API lengkap, koneksi DB langsung, lan karya berat.

Ngerti kabatisan Edge (Web API mung, ora ada raw TCP, eksekusi singkat) nyegah kesalahan sering saka nglayang database-heavy utawa kode Node-dependent ing runtime sing ora bisa nyengkuyung.

Milih runtime

Pamilihe

Kapan nggunake Edge

Kapan nggunake Node.js

Conto kendala nyata

Mengapa penting

Pitakon sing gegandhengan