Merge pull request #33 from ATNoG/docs/README

Added readme

Author: ThiagoAVicente

README.md

@@ -1,8 +1,85 @@
 # pei-nwdaf-data-storage
-Data storage service
 
+> Project for PEI evaluation 25/26
+
+## Overview
+
+Data storage service providing dual-database persistence layer for the NWDAF platform. Consumes processed network data from Kafka and stores it in both time-series (InfluxDB) and analytical (ClickHouse) databases, while exposing REST APIs for data retrieval.
+
+## Technologies
+
+- **Python** 3.13
+- **FastAPI** - REST API framework
+- **InfluxDB** - Time-series database for metrics
+- **ClickHouse** - Columnar analytical database
+- **Apache Kafka** (confluent_kafka) - Message streaming consumer
+- **Docker & Docker Compose** - Containerization
+- **uvicorn** - ASGI server
+- **pytest** - Testing framework
+
+## Architecture
+
+**Dual Database Strategy**:
+- **InfluxDB**: Optimized for time-series queries, network metrics storage, fast writes
+- **ClickHouse**: Optimized for analytical queries, aggregations, OLAP workloads
+
+## Key Features
+
+- **Kafka consumer**: Subscribes to `network.data.processed` topic
+- **Dual writes**: Simultaneously stores data in InfluxDB and ClickHouse
+- **REST API endpoints**: Query historical network data
+  - Cell metadata retrieval
+  - Time-range queries
+  - Latency data access
+  - Batch pagination support
+- **Data models**: Network performance metrics (RSRP, SINR, RSRQ, latency, CQI, datarate)
+- **Integration**: Provides data to ML service for training and processor for metadata
+
+## Quick Start
+
+```bash
+docker-compose up -d
+```
+
+## Database Connections
+
+- **InfluxDB**: Port 8086
+- **ClickHouse**: Port 8123 (HTTP), Port 9000 (TCP)
+
+## API Endpoints (Examples)
+
+- `/cells` - List all cells
+- `/cells/{cell_id}` - Get cell metadata
+- `/latency` - Query latency data
+- `/metrics` - Retrieve network metrics
+
+## Data Flow
+
+```
+Kafka (network.data.processed) →
+Storage Service →
+├── InfluxDB (time-series metrics)
+└── ClickHouse (analytical queries)
+```
+
+## Use Cases
+
+- Historical network performance analysis
+- Training data for ML models
+- Cell metadata for processor windowing
+- Time-range queries for analytics
+- Real-time metrics dashboards
+
+## Environment Variables
+
+Configure via `.env`:
+- Database connection strings
+- Kafka broker URLs
+- Service ports
+- Retention policies
+
+## Testing
 
-## To run
 ```bash
-docker-compose up -d 
+pytest tests/
 ```