Easysystem-designbasicsscaling

One server

Acceptance: 100.0%Solved by: 1

Statement

Assemble the simplest architecture for a small startup: an application server that takes client requests, and a database. Normal load is 150 requests per second, but during a marketing campaign traffic triples for 20 seconds. The system must stay within the SLO then as well. Hint: the app server’s “instances” parameter is horizontal scaling; the database scales only vertically (tier).

Constraints

p95 ≤ 250 ms, errors ≤ 0.1 %, budget $600/month.

Requirements

SimulationBuild from scratch

p95

≤ 250 ms

Errors

≤ 0.10 %

Budget

$600/mo

Users

5,000

Your architecture costs$0 / $600

★ within budget · ★★ ≤ 75 % · ★★★ ≤ 50 % of the budget

Scenarios (checked in order)

1Normal loadLoad
150 requests/s for 60 seconds: 70 % reads, 20 % writes, 10 % static.
60 s · 150 rps · R 70 / W 20 / S 10 %
2Marketing campaignSpike
From second 20, traffic triples for 20 seconds (450 requests/s).
90 s · 150 rps · R 70 / W 20 / S 10 % · ×3 from s 20 for 20 s

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