Problems / Scaling, medium
The API runs on a container platform that autoscales from 2 to 3 instances. Traffic needs more.
Free to open. Runs in your browser, no sign-up.
Success ≥ 99%, p99 ≤ 500 ms.
3,000 requests a second for 30 seconds: 90% reads, 10% writes.
What each component does in this design, and what calls it. The simulator mimics each one from these settings.
| Component | Its job here | Settings |
|---|---|---|
| Load balancerLoad balancer | Traffic enters here.Calls API (containers).Layer 4 balancers route by IP and port; layer 7 balancers read HTTP and can route by path or header. | – |
| API (containers)Container platform | Load balancer forwards to it.Calls Redis cache (checked first), Postgres.Orchestrators like Kubernetes restart failed containers and spread them across machines. | 300 slots · 2–3 instances |
| Redis cacheCache | API (containers) checks it first for reads.An in-memory cache like Redis usually answers in well under a millisecond inside one region. | 95% hit rate |
| PostgresSQL database | API (containers) reads it when Redis cache misses. API (containers) calls it for writes.Postgres runs one process per connection, which is why poolers like PgBouncer sit in front of busy databases. | 8 vCPU · 60 connections |
Try it first. Open one hint at a time if you get stuck.
Autoscaling can only add instances up to its maximum.
Look at “Instances” on the card.
Raise the maximum instances (and start with more).