Ukadirio na kupanga uwezo wa mfumo — kuhesabu mzigo unaotarajiwa, kiasi cha data, na mahitaji ya rasilimali — ni sehemu muhimu ya muundo wa mfumo. Mahesabu ya takriban "kwa kumbuka" husaidia maamuzi ya muundo (jinsi ya kuongeza kiwango, rasilimali gani zinahitajika) na ni kawaida katika mihadhara ya muundo.
Kwa nini ukadirio unamaanisha
Estimating scale informs DESIGN decisions:
→ how many servers? how much storage? what database? do you need sharding/caching?
→ understanding the SCALE (small vs massive) shapes the whole design
→ rough numbers guide whether/how to scale (don't over- or under-engineer)
Nini cha kukadiria (kwa kumbuka)
✓ TRAFFIC → users, requests/sec (QPS); read vs write ratio (e.g. 100:1 reads:writes)
→ peak vs average (design for peak); daily active users → requests
✓ STORAGE → data size per item × volume × growth over time → total storage (and growth rate)
✓ BANDWIDTH → data transferred per second (request size × QPS)
✓ MEMORY → cache size needed (e.g. cache the hot 20% of data)
→ rough estimates (order of magnitude) → good enough to inform design
