Menene matakunan ajiya a cikin gadar webi ta yau da kullun?

Question

Accepted Answer

Buƙatun yana gudana ta **maƙassan ajiya masu yawa**, kowa kusa da mai amfani yana aiki da sauri amma ke riƙe da karami. Manufar ita ce ba da amsa da bakowa (kusa da abokin ciniki) da ba tabbatacce ba sai muddin ba wani abu na sama ba ne na iya aiki amsa.

## Matakun, waje-ciki

```text
Browser → CDN → Reverse proxy → App/object cache → OPcache → Database
(closest to user, fastest)                            (closest to data)
```

- **Ajiyar burauzar** — ajiye abubuwan tsayi (JS, CSS, hotuna) da amsosin da ake iya ajiye akan na mai amfani. TTL ana sarrafa shi ta hanyar `Cache-Control`/`ETag`; abubuwan galibi suna samun TTL mai tsayi (rana–shekara) tare da jerin fayil da aka hash.
- **CDN** (CloudFront, Cloudflare) — ajiye abubuwan tsayi da wani lokaci abin sauri a gefen nodoci kusa da mai amfani. TTL daga mintuna (HTML) zuwa shekara (abubuwa mara jiya).
- **Reverse proxy** (Varnish, nginx) — ajiye shafuka cikakke ko bangare a gabankaro. TTL daga dakika zuwa mintuna don shafuka masu zafi; yana goyan baya nazzar kan canja.
- **Cache ajiya / abu** (Redis, Memcached) — ajiye sakamakon da aka kirkiruji, sakamakon buƙatun DB, kumbuka, bangare da aka kewaita. TTL daga dakika zuwa sa'a, da kuma rashin tabbatarwa na bayyane.
- **OPcache** — ajiye **bytecode PHP da aka tsara** a ajiya ta halitta don ba a sake duba jerin ba a buƙatun gida. Yana aiki har sai saka jiya wuri na code.
- **Buƙatun DB / buffer cache** — yajin bayanan yana riƙe da shafuka masu zafi da (a wasu injin) sakamakon buƙatun a halitta, jijiya karantawa faifai.

## Yadda zai fahimci game da su

```text
for each layer outward → inward:
  if layer has fresh copy → return it (stop here)   // a hit; cheapest possible
  else → ask the next layer in                      // a miss; falls through
origin (app + DB) → does the real work, fills caches on the way back out
```

Kowane mataki ya canja **samun matsaloli don sauri** : matakun waje suni da gida amma mafi yawa a daga ba na nan ba, don haka ajiye TTL mai tsayi + hash abubuwa da genu ta gaskiya da nuffin bayyane da TTL kasar + rashin tabbatarwa akan abubuwan jujjuyawal.

## Me ya sa haka mahalaci

Galibi yajin bayanan ajiya a cikakken mataki ta sauri da raguwa cargo. Sanin abin da kowane mataki ya riƙe da kuma TTL na buƙatunshi ya bai ni ikon ajiye ajiya a waje da tabbas taimakawa, guje saurin abubuwan tsofaffin bayanan, da tunani akan dalilin da bai bayyana ba haka jiya (menene mataki yana aiki tsufa suruta).