Centralized Logging System (Spring Boot WebFlux, R2DBC, Docker)

Requirements implemented:

• Java 17+, Spring Boot 3.x WebFlux, PostgreSQL with R2DBC, Maven multi-module, Docker/Compose
• Event-driven, bounded concurrency with backpressure
• TCP/UDP log collection, enrichment via blacklist, forwarding to central server
• Storage and querying with filtering; metrics on collector and server
• Simulated Linux/Windows clients generating logs every 1–2s

Build

mvn clean package -DskipTests

Run

docker-compose up --build

Services:

• Postgres: postgres:5432
• Log Server API: http://localhost:8080
• Log Collector: TCP 9000, UDP 9001, Metrics http://localhost:8090/metrics

API

• Ingest metrics:

curl http://localhost:8080/metrics

curl http://localhost:8090/metrics

curl http://localhost:8080/logs?is.blacklisted=true&limit=5

curl http://localhost:8080/logs?service=windows-client&level=ERROR&username=Administrator&is.blacklisted=false&limit=20&sort=desc

curl http://localhost:8080/logs?service=linux-client&level=INFO&username=root&limit=5

• Query logs with filters:

curl "http://localhost:8080/logs?service=linux-client&level=INFO&username=root&blacklisted=false&limit=20&sort=desc"

curl http://localhost:8080/logs?service=linux-client&limit=10

Concurrency & Backpressure

• Reactive streams (Project Reactor) throughout
• Non-blocking TCP/UDP using Reactor Netty
• Bounded queues using onBackpressureBuffer with limits
• Controlled parallelism via Reactor schedulers (bounded)
• Graceful shutdown hooks close sockets and stop generators

Environment

Copy .env.example to .env to override defaults.

Tests

Run:

mvn test

Includes parsing/validation, blacklist enrichment, DB filter logic, and metrics unit tests.