Cryptocurrency Statistics System

This project consists of two Node.js servers that work together to collect and expose cryptocurrency statistics.

Project Structure

/
├── api-server/     # API server for exposing cryptocurrency statistics
├── worker-server/  # Worker server for triggering data collection

Components

1. API Server:

   • Exposes endpoints for retrieving cryptocurrency statistics
   • Stores cryptocurrency data in MongoDB
   • Subscribes to events from the worker server via NATS

2. Worker Server:

   • Runs a background job every 15 minutes to trigger data collection
   • Publishes events to the API server via NATS

3. MongoDB:

   • Stores cryptocurrency statistics
   • Used by the API server to retrieve data

4. NATS:

   • Facilitates communication between the API server and worker server

Data Flow

1. The worker server runs a background job every 15 minutes
2. When the job runs, it publishes an event to NATS with { "trigger": "update" }
3. The API server receives this event and calls storeCryptoStats()
4. storeCryptoStats() fetches data from CoinGecko API and stores it in MongoDB
5. When a user requests statistics via the API, the API server retrieves the data from MongoDB

Setup and Running

Please refer to the README files in the api-server and worker-server directories for specific setup instructions.

Quick Start

1. Start MongoDB:

   docker run --name mongodb -d \
       -p 27017:27017 \
       -e MONGO_INITDB_ROOT_USERNAME=admin \
       -e MONGO_INITDB_ROOT_PASSWORD=password \
       mongo
   
   

2. Start NATS:

   docker run -p 4222:4222 -p 8222:8222 -p 6222:6222 --name nats-server -d nats:latest
   

3. Install and start the API server:

   cd api-server
   npm install
   npm run dev
   

4. Install and start the worker server:

   cd worker-server
   npm install
   npm run dev
   

API Endpoints

GET /stats

Get the latest statistics for a specific cryptocurrency.

Query Parameters:

• coin: The cryptocurrency to get statistics for (bitcoin, ethereum, or matic-network)

Example:

GET /stats?coin=bitcoin

GET /update?trigger=update

Trigger an immediate update of cryptocurrency statistics.

Example:

GET /update?trigger=update

GET /deviation

Get the standard deviation of price for a specific cryptocurrency over the last 100 records.

Query Parameters:

• coin: The cryptocurrency to calculate deviation for (bitcoin, ethereum, or matic-network)

Example:

GET /deviation?coin=bitcoin

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