Add stock data demo

Author: lio-p

stock-data-demo/.gitignore

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+# Environment variables
+.env*
+!.env.example
+env.local
+
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Production builds
+.next/
+out/
+dist/
+build/
+
+# Runtime data
+*.pid
+*.seed
+*.pid.lock
+
+# Logs
+logs
+*.log
+
+# Coverage directory used by tools like istanbul
+coverage/
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Temporary files
+*.tmp
+*.temp
+
+# Archives
+*.tar.gz
+stock-data.tar.gz
+
+# Frontend backup
+frontend-backup/
+
+# Application logs
+app.log 

stock-data-demo/README.md

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+# Stock Data Demo Platform
+
+A unified, high-throughput stock data demo platform that combines real-time data ingestion with advanced visualization capabilities. This integrated system handles WebSocket data from Polygon.io, stores it in ClickHouse, and provides both administrative controls and sophisticated stock data visualization.
+
+
+
+## 🚀 **Getting Started**
+
+### **Prerequisites**
+
+- Node.js 18+
+- Access to ClickHouse cluster
+- Polygon.io API credentials
+
+### **Installation & Startup**
+
+```bash
+# Install all dependencies (both backend and frontend)
+npm install
+
+# Start the integrated platform
+npm start
+
+# For development with hot reloading
+npm run dev
+```
+
+### **Access Points**
+
+- **🏠 Landing Page**: `http://localhost:34567/`
+- **📈 Stock Charts UI**: `http://localhost:34567/stocks` _(live candlestick charts)_
+- **🎛️ Admin Controls**: `http://localhost:34567/admin`
+- **📊 Health API**: `http://localhost:34567/health`
+- **🔌 Metrics API**: `http://localhost:34567/metrics`
+
+## 🏗️ **Application Structure**
+
+```
+stock-data/
+├── app.js                 # Main Express server (ingestion + routing)
+├── package.json           # Combined dependencies
+├── public/                # Static assets and admin UI
+│   ├── index.html         # Unified landing page
+│   ├── admin.html         # Ingestion monitoring UI
+│   ├── styles.css         # Admin UI styles
+│   └── app.js            # Admin UI JavaScript
+├── frontend/              # Next.js stock visualization app
+│   ├── src/
+│   │   ├── components/    # Stock UI components
+│   │   │   ├── liveDataTable.tsx
+│   │   │   └── liveStockChart.tsx
+│   │   ├── queryHandlers/ # ClickHouse query logic
+│   │   ├── types/         # TypeScript definitions
+│   │   └── app/          # Next.js app structure
+│   ├── next.config.mjs    # Next.js configuration
+│   └── tsconfig.json      # TypeScript configuration
+└── README.md             # This documentation
+```
+
+## 🔧 **Configuration**
+
+Key configurable parameters in the `StockDataIngester` class:
+
+```javascript
+this.maxBatchSize = 1000; // Records per batch
+this.maxMemoryUsage = 100 * 1024 * 1024; // 100MB memory limit
+this.batchTimeout = 5000; // 5 second flush interval
+this.maxConcurrentInserts = 10; // Max parallel ClickHouse inserts
+this.maxReconnectAttempts = 10; // WebSocket reconnection attempts
+```
+
+## 📊 **Platform Capabilities**
+
+### **Data Ingestion Service**
+
+- **Throughput**: 100,000+ messages per second
+- **Memory Management**: Auto-managed with 100MB default limit
+- **Latency**: Sub-second batch processing
+- **Availability**: Automatic recovery from most failure scenarios
+- **Data Types**: Real-time trades and quotes from all US equities
+
+### **Visualization Frontend**
+
+- **Real-time Updates**: Live data refreshes every 100ms
+- **Interactive Charts**: Candlestick charts with volume indicators
+- **Time Window Selection**: 4 different aggregation periods (5min to 1day) with smart refresh rates
+- **Chart Performance**: Optimized refresh intervals from 500ms to 60s based on time window
+- **Data Quality**: Direct ClickHouse integration for minimal latency
+- **UI Framework**: Modern React with ClickHouse UI components
+
+### **Administrative Interface**
+
+- **Live Monitoring**: Real-time connection status and throughput metrics
+- **Control Panel**: Start, stop, pause, and restart data ingestion
+- **Performance Tracking**: Memory usage, queue lengths, processing rates
+- **Connection History**: Detailed logs of connection events and failures
+
+## 🔗 **Integration Architecture**
+
+### **Data Flow**
+
+1. **WebSocket Ingestion** → Polygon.io real-time feeds
+2. **Data Processing** → Filtering, transformation, and batching
+3. **Database Storage** → ClickHouse with optimized async inserts
+4. **UI Data Access** → Direct ClickHouse queries from frontend
+5. **Administrative Monitoring** → Express API endpoints
+
+### **Technology Stack**
+
+- **Backend**: Node.js + Express (JavaScript)
+- **Frontend**: Next.js + React (TypeScript)
+- **Database**: ClickHouse with optimized settings
+- **UI Components**: ClickHouse UI + Custom Components
+- **Charts**: Chart.js with financial data extensions and real-time streaming
+- **Time Windows**: Multiple aggregation periods (1s, 1m, 2m, 1h buckets) with adaptive refresh rates
+- **Real-time**: WebSocket connections + polling
+
+## 🎮 **Control API**
+
+```bash
+# Pause data ingestion
+curl -X POST http://localhost:34567/control/pause
+
+# Resume data ingestion
+curl -X POST http://localhost:34567/control/start
+
+# Stop ingestion completely
+curl -X POST http://localhost:34567/control/stop
+
+# Restart with clean reconnection
+curl -X POST http://localhost:34567/control/restart
+```
+
+## 📈 **Monitoring & Metrics**
+
+### **Health Check Response**
+
+```json
+{
+  "status": "connected",
+  "connected": true,
+  "paused": false,
+  "uptime": 1234.5,
+  "totalUptime": 5678.9,
+  "tradesInserted": 125847,
+  "quotesInserted": 98234,
+  "totalRecordsInserted": 224081,
+  "processedMessages": 15678,
+  "droppedMessages": 23,
+  "memoryUsageMB": 45,
+  "runningInserts": 3,
+  "queueLength": 0,
+  "connectionHistory": [...],
+  "statusMessage": "Active - Receiving data"
+}
+```
+
+## 🚨 **Production Considerations**
+
+### **Performance Optimization**
+
+- ClickHouse async inserts with 5MB batches
+- Concurrent insert limiting (max 10 parallel)
+- Memory pressure detection and handling
+- Queue overflow protection
+
+### **Reliability Features**
+
+- Exponential backoff reconnection (up to 10 attempts)
+- Stale connection detection (60+ seconds timeout)
+- Graceful shutdown with data preservation
+- Comprehensive error logging and recovery
+
+### **Scalability Notes**
+
+- Horizontal scaling: Run multiple ingestion instances
+- Database scaling: ClickHouse cluster configuration
+- Frontend scaling: CDN deployment for static assets
+- Load balancing: Multiple Express instances behind proxy
+
+## 🔧 **Development**
+
+### **Frontend Development**
+
+```bash
+# Build frontend for production
+npm run frontend:build
+
+# Run frontend in development mode
+npm run frontend:dev
+
+# Run only the backend
+npm run backend
+```