Five nines across regions

expert

Scenario & brief

A payments platform must reach 99.995% availability and survive the loss of an entire region. Three AZs and a Multi-AZ database top out around four-nines — five-nines needs more than one region.

Targets: 99.995% availability, critical durability, p99 ≤ 160 ms, under $2,500/mo.

Deploy active-active across regions, keep three AZs with a Multi-AZ database and a read replica for in-region resilience, add a cache, and use a Savings Plan on Graviton to keep the doubled footprint affordable.

4,000 rps peakp99 ≤ 160ms99.995% availdurability: criticalbudget $2,500/mo

App Servers

Compute

Instance class

Scaling

Instances (static)

2instances

Availability Zones

Purchasing

Deployment footprint

System health

Erupting · SLA breach

/ 100

Score

SLA not met yet

Monthly cost

$653

Budget $2,500/mo · within budget

Metrics

Capacity43

Availability90

Durability25

Cost efficiency90

Requirements

Peak capacity — 3600 rps compute · 1700 rps db (need ≥ 4000 rps)
p99 latency — ~194 ms (need ≤ 160 ms)
Availability — 99.95% (need ≥ 100.00%)
Durability — at risk (need redundancy + backups)
Budget — $653/mo (need ≤ $2500/mo)

Advisor

Compute tops out at ~3600 rps but peak demand is 4000 rps — requests will queue.
The database is saturated at peak — add a cache to shed read load, or scale it up.
Enable automated backups to satisfy the durability requirement.

Discussion

No comments yet. Be the first to start the discussion.

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