Global-scale datastore

expert

Scenario & brief

A key-value platform serves 20,000 rps worldwide and must hold 99.995% availability with p99 ≤ 100 ms, critical durability — under $3,000/mo. You start single-region with under-provisioned DynamoDB, no CDN, no cache.

Scale it globally: set the deployment footprint to active-active multi-region, add a CDN for edge caching and an ElastiCache tier to shield the datastore, and switch DynamoDB to on-demand so it absorbs global spikes without throttling. Keep every tier lean — multi-region doubles the bill.

20,000 rps peakp99 ≤ 100ms99.995% availdurability: criticalbudget $3,000/mo

Add components

Decide what this architecture actually needs — not every option belongs here.

App Servers

Compute

Instance class

Scaling

Instances (static)

8instances

Availability Zones

Purchasing

Deployment footprint

System health

Erupting · SLA breach

/ 100

Score

SLA not met yet

Monthly cost

$4,579

Budget $3,000/mo · $1,579 over

Metrics

Capacity48

Availability50

Durability100

Cost efficiency28

Requirements

Peak capacity — 52000 rps compute · 9600 rps db (need ≥ 20000 rps)
p99 latency — ~132 ms (need ≤ 100 ms)
Availability — 99.50% (need ≥ 100.00%)
Durability — protected (need redundancy + backups)
Budget — $4579/mo (need ≤ $3000/mo)

Advisor

The database is saturated at peak — add a cache to shed read load, or scale it up.
Compute runs in a single AZ — spread across ≥2 AZs (with ≥2 instances) to meet the availability target.

Discussion

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For learning purposes only. Costs and capacities are illustrative, not live AWS prices. Not affiliated with or endorsed by Amazon Web Services.