Right-size DynamoDB

intermediate

Scenario & brief

A key-value service with steady, predictable traffic (peak ~6,000 rps) runs DynamoDB with hundreds of provisioned capacity units it never uses — and the compute tier is single-AZ.

Targets: p99 ≤ 180 ms, 99.95% availability, critical durability, under $400/mo.

6,000 rps peakp99 ≤ 180ms99.95% availdurability: criticalbudget $400/mo

App Servers

Compute

Instance class

Scaling

Instances (static)

3instances

Availability Zones

Purchasing

System health

Erupting · SLA breach

/ 100

Score

SLA not met yet

Monthly cost

$982

Budget $400/mo · $582 over

Metrics

Capacity90

Availability50

Durability100

Cost efficiency0

Requirements

Peak capacity — 5400 rps compute · 72000 rps db (need ≥ 6000 rps)
p99 latency — ~134 ms (need ≤ 180 ms)
Availability — 99.50% (need ≥ 99.95%)
Durability — protected (need redundancy + backups)
Budget — $982/mo (need ≤ $400/mo)

Advisor

Compute tops out at ~5400 rps but peak demand is 6000 rps — requests will queue.
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.