MushyBook
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Pick the right DynamoDB mode

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Scenario & brief

This table sees flat traffic that briefly spikes to 12,000 rps. It's on provisioned capacity sized far below the spike, so writes throttle exactly when it matters. Cranking provisioned units high enough to cover the spike would mean paying for that ceiling 24×7.

Targets: p99 ≤ 130 ms, 99.95% availability, critical durability, under $700/mo.

12,000 rps peakp99 ≤ 130ms99.95% availdurability: criticalbudget $700/mo

App Servers

Compute

3instances

System health

Erupting · SLA breach

28

/ 100

Score

SLA not met yet

Monthly cost

$899

Budget $700/mo · $199 over

Metrics

Capacity40
Availability50
Durability100
Cost efficiency43

Requirements

  • Peak capacity — 10800 rps compute · 4800 rps db (need ≥ 12000 rps)
  • p99 latency — ~185 ms (need ≤ 130 ms)
  • Availability — 99.50% (need ≥ 99.95%)
  • Durability — protected (need redundancy + backups)
  • Budget — $899/mo (need ≤ $700/mo)

Advisor

  • Compute tops out at ~10800 rps but peak demand is 12000 rps — requests will queue.
  • 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.