Problems / Security, medium
Attackers replay leaked passwords against your login at 5,000 req/s. Every attempt hits the database.
Free to open. Runs in your browser, no sign-up.
Success ≥ 98% for real users, block ≥ 95% of the attack.
1,500 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 Postgres.Little's law: throughput ≈ concurrency ÷ latency. 200 slots at 50 ms serve about 4,000 req/s. | 4 replicas × 200 slots · timeout 2.0 s |
| PostgresSQL database | API calls it.Postgres runs one process per connection, which is why poolers like PgBouncer sit in front of busy databases. | 4 vCPU · 60 connections |
Try it first. Open one hint at a time if you get stuck.
Each attempt costs a database query.
Stop them before they reach the API.
Add a WAF and bot management in front (credential-stuffing rules).