Problems / Resilience, easy
The search backend takes 80–200 ms. The API gives up after 100 ms.
Free to open. Runs in your browser, no sign-up.
Success ≥ 99%, p99 ≤ 1 s.
800 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.Layer 4 balancers route by IP and port; layer 7 balancers read HTTP and can route by path or header. | – |
| APIApp service | Load balancer forwards to it.Calls Search backend.Little's law: throughput ≈ concurrency ÷ latency. 200 slots at 50 ms serve about 4,000 req/s. | 3 replicas × 200 slots · timeout 100 ms |
| Search backendSQL database | API calls it.Postgres runs one process per connection, which is why poolers like PgBouncer sit in front of busy databases. | 8 vCPU · 200 connections |
Try it first. Open one hint at a time if you get stuck.
Compare the timeout with the dependency’s p99.
Timeouts should sit above normal latency.
Raise the timeout above the dependency’s p99 (“set the API timeout to 1 s”).