Apa wae papat sinyal emas saka monitoring?

Question

Accepted Answer

Saka buku SRE Google, papat sinyal emas yaiku **latency, traffic, errors, lan saturation**. Yen sampeyan bisa mung ngukur papat barang babagan sistem sing ngadeg mengkono, ukuran iki — bebarengan nyukup nangkep sabayan gedhene masalah.

## Papat sinyal

```text
LATENCY     how long a request takes
            → split SUCCESSFUL vs FAILED latency (a fast 500 isn't "fast")
            → track percentiles (p50/p95/p99), not averages

TRAFFIC     how much demand the system is under
            → requests/sec, transactions/sec, concurrent sessions

ERRORS      rate of failing requests
            → explicit (HTTP 500) and implicit (wrong content, too slow)

SATURATION  how "full" the system is — its most constrained resource
            → CPU, memory, I/O, queue depth; a leading indicator of trouble
```

## Sebabe papat iki nyukup kanggo mbahas akeh masalah

Latency lan errors iku sing karasakne users **langsung**. Traffic nerangake **context beban** (lonjakan latency nalika kenaikan traffic 10x marang mbeda luwih apa ing baseline). Saturation yaiku **leading indicator** — mundhak sadurunge latency lan errors, menehi peringatan sayege ora cidera users.

```text
saturation climbs → latency rises → errors appear → users complain
     ^ warning here, while there's still time to act
```

## Beda karo USE lan RED

Sinyal emas minangka siji saka telu framework sing sambungan; padha klumbu akeh lan njupuk tanda-tanda urip sing padha saka sudut beda.

```text
GOLDEN  latency, traffic, errors, saturation   → user-facing services (general)
RED     Rate, Errors, Duration                 → request-driven services (a subset)
USE     Utilization, Saturation, Errors        → resources/infra (per device)
```

RED asike sinyal emas tanpa saturation, dituduhake babagan requests; USE yaiku resource-centric (terapake per disk, NIC, CPU). Guna RED kanggo layanan, USE kanggo hardware, sinyal emas minangka default umum.

## Kenapa penting

Monitoring kabeh nggawa bising lan pocongan buta; monitoring nglewer ninggal kowe lumiyang buta. Sinyal emas minangka set minimal sing proven ngikat dashboard lan alert marang pengalaman user nalika isih muncul saturation awal — mula kowe entuk peringatan sadurunge insiden tinimbang post-mortem sawise.