Apa iku layanan mesh lan napa sampeyan bakal nggunakake?

Question

Accepted Answer

Sebuah **layanan mesh** (Istio, Linkerd) mindhah cross-cutting networking concerns — retries, timeouts, mTLS, traffic routing, observability — **metu saka kode aplikasi** lan menyang layer infrastruktur jaringan **sidecar proxies**.

## Cara kerjane

Saben instansi layanan mlaku sajane **sidecar proxy** (contone, Envoy). Kabeh traffic mlaku liwat proxies, sing nggawe **data plane**; **control plane** nata wong-wong.

```text
┌─────────────────┐        ┌─────────────────┐
│ Service A       │        │ Service B       │
│  app  ⇄ [proxy] │◀──────▶│ [proxy] ⇄  app  │
└─────────────────┘  mTLS  └─────────────────┘
        ▲ configured by ▲
        └──── Control Plane (Istio/Linkerd) ────┘
```

## Apa sing diwenehake

- **mTLS** antarane layanan kanthi otomatis (tanpa owah-owahan aplikasi).
- **Resilience** — retries, timeouts, circuit breaking ing proxy.
- **Traffic management** — canary, A/B, weighted routing.
- **Observability** — metrics seragam, traces, logs.

## Conto policy

```yaml
# shift 10% of traffic to v2 (canary), no code change
route:
  - destination: { host: orders, subset: v1 }
    weight: 90
  - destination: { host: orders, subset: v2 }
    weight: 10
```

## Trade-offs

A mesh nambah latency (hop tambahan), resource overhead (proxy siji per pod), lan kompleksitas operasional nyata.

## Napa iku penting

A mesh standardisasi resilience, security, lan observability ing saben layanan tanpa saben tim ngetrapake maneh ing basa-basa beda.

Namun berat: mung adopsi nalika sampeyan duwe layanan cukup yen logic jaringan duplikat ngluwihi biaya operasional mesh.