Lab 3

Microservices

Scale the Hot Path

A campaign spikes video traffic. Clone the whole monolith vs. add replicas to just the Video service. Watch cost & latency.

🔥 Marketing campaign — video traffic3× load

calmviral spike

Monolith — clone the whole app

Identity

Catalog

Payment

Video

Notify

Reports

Latency

370ms

Cost

6u

Idle copies

0

wasted modules

Microservices — scale only Video

Identity

×1

Catalog

×1

Payment

×1

Notify

×1

Reports

×1

🎬 Video service · 1 replica

V1

Latency

370ms

Cost

6u

Idle copies

0

nothing wasted

What just happened

▹Only the Video service is hot during a campaign — but the monolith forces you to clone all 6 modules to add capacity.
▹Microservices scale the hot path alone: add Video replicas, leave everything else at one instance.
▹Same latency, a fraction of the cost — and no idle copies of Payment/Reports burning money.