# Data Collector System Documentation

## Overview

The Data Collector System provides a robust, scalable framework for collecting real-time market data from cryptocurrency exchanges. It features comprehensive health monitoring, automatic recovery, centralized management, and a modular exchange-based architecture designed for production trading environments.

This documentation covers the **core collector components**. For the high-level service layer that orchestrates these collectors, see [Data Collection Service](../services/data_collection_service.md).

## Key Features

### 🏗️ **Modular Exchange Architecture**
- **Exchange-Based Organization**: Each exchange has its own implementation folder
- **Factory Pattern**: Easy creation of collectors from any supported exchange
- **Standardized Interface**: Consistent API across all exchange implementations
- **Scalable Design**: Easy addition of new exchanges (Binance, Coinbase, etc.)

### 🔄 **Auto-Recovery & Health Monitoring**
- **Heartbeat System**: Continuous health monitoring with configurable intervals
- **Auto-Restart**: Automatic restart on failures with exponential backoff
- **Connection Recovery**: Robust reconnection logic for network interruptions
- **Data Freshness Monitoring**: Detects stale data and triggers recovery

### 🎛️ **Centralized Management**
- **CollectorManager**: Supervises multiple collectors with coordinated lifecycle
- **Dynamic Control**: Enable/disable collectors at runtime without system restart
- **Global Health Checks**: System-wide monitoring and alerting
- **Graceful Shutdown**: Proper cleanup and resource management

### 📊 **Comprehensive Monitoring**
- **Real-time Status**: Detailed status reporting for all collectors
- **Performance Metrics**: Message counts, uptime, error rates, restart counts
- **Health Analytics**: Connection state, data freshness, error tracking
- **Conditional Logging**: Enhanced logging with configurable verbosity (see [Logging System](logging.md))
- **Multi-Timeframe Support**: Sub-second to daily candle aggregation (1s, 5s, 10s, 15s, 30s, 1m, 5m, 15m, 1h, 4h, 1d)

### 🛢️ **Database Integration**
- **Repository Pattern**: All database operations use the centralized `database/operations.py` module
- **No Raw SQL**: Clean API through `MarketDataRepository` and `RawTradeRepository` classes
- **Automatic Transaction Management**: Sessions, commits, and rollbacks handled automatically
- **Configurable Duplicate Handling**: `force_update_candles` parameter controls duplicate behavior
- **Real-time Storage**: Completed candles automatically saved to `market_data` table
- **Raw Data Storage**: Optional raw WebSocket data storage via `RawTradeRepository`
- **Custom Error Handling**: Proper exception handling with `DatabaseOperationError`
- **Health Monitoring**: Built-in database health checks and statistics
- **Connection Pooling**: Efficient database connection management through repositories

## Architecture

```
┌─────────────────────────────────────────────────────────────┐
│                   CollectorManager                          │
│  ┌─────────────────────────────────────────────────────┐    │
│  │              Global Health Monitor                  │    │
│  │  • System-wide health checks                       │    │
│  │  • Auto-restart coordination                       │    │
│  │  • Performance analytics                           │    │
│  └─────────────────────────────────────────────────────┘    │
│                           │                                 │
│  ┌─────────────────┐  ┌─────────────────┐  ┌──────────────┐ │
│  │  OKX Collector  │  │Binance Collector│  │   Custom     │ │
│  │                 │  │                 │  │  Collector   │ │
│  │ • Health Monitor│  │ • Health Monitor│  │ • Health Mon │ │
│  │ • Auto-restart  │  │ • Auto-restart  │  │ • Auto-resta │ │
│  │ • Data Validate │  │ • Data Validate │  │ • Data Valid │ │
│  └─────────────────┘  └─────────────────┘  └──────────────┘ │
└─────────────────────────────────────────────────────────────┘
                              │
                    ┌─────────────────┐
                    │   Data Output   │
                    │                 │
                    │ • Callbacks     │
                    │ • Redis Pub/Sub │
                    │ • Database      │
                    └─────────────────┘
```

### Exchange Module Structure

The modular architecture organizes exchange implementations:

```
data/
├── base_collector.py           # Abstract base classes
├── collector_manager.py        # Cross-platform collector manager
├── aggregator.py              # Cross-exchange data aggregation
├── exchanges/                 # Exchange-specific implementations
│   ├── __init__.py           # Main exports and factory
│   ├── registry.py           # Exchange registry and capabilities
│   ├── factory.py            # Factory pattern for collectors
│   └── okx/                  # OKX implementation
│       ├── __init__.py       # OKX exports
│       ├── collector.py      # OKXCollector class
│       └── websocket.py      # OKXWebSocketClient class
│   └── binance/              # Future: Binance implementation
│       ├── __init__.py
│       ├── collector.py
│       └── websocket.py
```

## Quick Start

### 1. Using Exchange Factory (Recommended)

```python
import asyncio
from data.exchanges import ExchangeFactory, ExchangeCollectorConfig, create_okx_collector
from data.base_collector import DataType
from utils.logger import get_logger

async def main():
    # Create logger for the collector
    logger = get_logger('okx_collector', verbose=True)
    
    # Method 1: Using factory with configuration
    config = ExchangeCollectorConfig(
        exchange='okx',
        symbol='BTC-USDT',
        data_types=[DataType.TRADE, DataType.ORDERBOOK],
        auto_restart=True,
        health_check_interval=30.0,
        store_raw_data=True
    )
    
    collector = ExchangeFactory.create_collector(config, logger=logger)
    
    # Method 2: Using convenience function
    okx_collector = create_okx_collector(
        symbol='ETH-USDT',
        data_types=[DataType.TRADE, DataType.ORDERBOOK],
        logger=logger
    )
    
    # Add data callback
    def on_trade_data(data_point):
        print(f"Trade: {data_point.symbol} - {data_point.data}")
    
    collector.add_data_callback(DataType.TRADE, on_trade_data)
    
    # Start collector
    await collector.start()
    
    # Let it run
    await asyncio.sleep(60)
    
    # Stop collector
    await collector.stop()

asyncio.run(main())
```

### 2. Creating Multiple Collectors with Manager

```python
import asyncio
from data.exchanges import ExchangeFactory, ExchangeCollectorConfig
from data.base_collector import DataType
from data.collector_manager import CollectorManager
from utils.logger import get_logger

async def main():
    # Create manager with logging
    manager_logger = get_logger('collector_manager', verbose=True)
    manager = CollectorManager(logger=manager_logger)
    
    # Create multiple collectors using factory
    configs = [
        ExchangeCollectorConfig('okx', 'BTC-USDT', [DataType.TRADE, DataType.ORDERBOOK]),
        ExchangeCollectorConfig('okx', 'ETH-USDT', [DataType.TRADE]),
        ExchangeCollectorConfig('okx', 'SOL-USDT', [DataType.ORDERBOOK])
    ]
    
    # Create collectors with individual loggers
    for config in configs:
        collector_logger = get_logger(f'okx_{config.symbol.lower().replace("-", "_")}')
        collector = ExchangeFactory.create_collector(config, logger=collector_logger)
        manager.add_collector(collector)
    
    print(f"Created {len(manager.list_collectors())} collectors")
    
    # Start all collectors
    await manager.start()
    
    # Monitor
    await asyncio.sleep(60)
    
    # Stop all
    await manager.stop()

asyncio.run(main())
```

## API Reference

### BaseDataCollector

The abstract base class that all data collectors must inherit from.

#### Constructor

```python
def __init__(self, 
             exchange_name: str,
             symbols: List[str],
             data_types: Optional[List[DataType]] = None,
             component_name: Optional[str] = None,
             auto_restart: bool = True,
             health_check_interval: float = 30.0,
             logger: Optional[logging.Logger] = None,
             log_errors_only: bool = False)
```

**Parameters:**
- `exchange_name`: Name of the exchange (e.g., 'okx', 'binance')
- `symbols`: List of trading symbols to collect data for
- `data_types`: Types of data to collect (default: [DataType.CANDLE])
- `component_name`: Name for logging (default: based on exchange_name)
- `auto_restart`: Enable automatic restart on failures (default: True)
- `health_check_interval`: Seconds between health checks (default: 30.0)
- `logger`: Logger instance for conditional logging (default: None)
- `log_errors_only`: Only log error-level messages (default: False)

#### Abstract Methods

Must be implemented by subclasses:

```python
async def connect(self) -> bool
async def disconnect(self) -> None
async def subscribe_to_data(self, symbols: List[str], data_types: List[DataType]) -> bool
async def unsubscribe_from_data(self, symbols: List[str], data_types: List[DataType]) -> bool
async def _process_message(self, message: Any) -> Optional[MarketDataPoint]
async def _handle_messages(self) -> None
```

#### Public Methods

```python
async def start() -> bool                    # Start the collector
async def stop(force: bool = False) -> None  # Stop the collector
async def restart() -> bool                  # Restart the collector

# Callback management
def add_data_callback(self, data_type: DataType, callback: Callable) -> None
def remove_data_callback(self, data_type: DataType, callback: Callable) -> None

# Symbol management
def add_symbol(self, symbol: str) -> None
def remove_symbol(self, symbol: str) -> None

# Status and monitoring
def get_status(self) -> Dict[str, Any]
def get_health_status(self) -> Dict[str, Any]

# Data validation
def validate_ohlcv_data(self, data: Dict[str, Any], symbol: str, timeframe: str) -> OHLCVData
```

#### Conditional Logging Methods

All collectors support conditional logging (see [Logging System](logging.md) for details):

```python
def _log_debug(self, message: str) -> None      # Debug messages (if not errors-only)
def _log_info(self, message: str) -> None       # Info messages (if not errors-only)
def _log_warning(self, message: str) -> None    # Warning messages (if not errors-only)
def _log_error(self, message: str, exc_info: bool = False) -> None    # Always logged
def _log_critical(self, message: str, exc_info: bool = False) -> None # Always logged
```

#### Status Information

The `get_status()` method returns comprehensive status information:

```python
{
    'exchange': 'okx',
    'status': 'running',                    # Current status
    'should_be_running': True,               # Desired state
    'symbols': ['BTC-USDT', 'ETH-USDT'],      # Configured symbols
    'data_types': ['ticker'],                  # Data types being collected
    'auto_restart': True,                      # Auto-restart enabled
    'health': {
        'time_since_heartbeat': 5.2,            # Seconds since last heartbeat
        'time_since_data': 2.1,                 # Seconds since last data
        'max_silence_duration': 300.0           # Max allowed silence
    },
    'statistics': {
        'messages_received': 1250,                # Total messages received
        'messages_processed': 1248,                # Successfully processed
        'errors': 2,                              # Error count
        'restarts': 1,                            # Restart count
        'uptime_seconds': 3600.5,                 # Current uptime
        'reconnect_attempts': 0,                  # Current reconnect attempts
        'last_message_time': '2023-...',           # ISO timestamp
        'connection_uptime': '2023-...',           # Connection start time
        'last_error': 'Connection failed',          # Last error message
        'last_restart_time': '2023-...'            # Last restart time
    }
}
```

#### Health Status

The `get_health_status()` method provides detailed health information:

```python
{
    'is_healthy': True,                          # Overall health status
    'issues': [],                               # List of current issues
    'status': 'running',                         # Current collector status
    'last_heartbeat': '2023-...',                 # Last heartbeat timestamp
    'last_data_received': '2023-...',             # Last data timestamp
    'should_be_running': True,                    # Expected state
    'is_running': True                           # Actual running state
}
```

### CollectorManager

Manages multiple data collectors with coordinated lifecycle and health monitoring.

#### Constructor

```python
def __init__(self,
             manager_name: str = "collector_manager",
             global_health_check_interval: float = 60.0,
             restart_delay: float = 5.0,
             logger: Optional[logging.Logger] = None,
             log_errors_only: bool = False)
```

**Parameters:**
- `manager_name`: Name for the manager (used in logging)
- `global_health_check_interval`: Seconds between global health checks
- `restart_delay`: Delay between restart attempts
- `logger`: Logger instance for conditional logging (default: None)
- `log_errors_only`: Only log error-level messages (default: False)

#### Public Methods

```python
# Collector management
def add_collector(self, collector: BaseDataCollector, config: Optional[CollectorConfig] = None) -> None
def remove_collector(self, collector_name: str) -> bool
def enable_collector(self, collector_name: str) -> bool
def disable_collector(self, collector_name: str) -> bool

# Lifecycle management
async def start() -> bool
async def stop() -> None
async def restart_collector(self, collector_name: str) -> bool
async def restart_all_collectors(self) -> Dict[str, bool]

# Status and monitoring
def get_status(self) -> Dict[str, Any]
def get_collector_status(self, collector_name: str) -> Optional[Dict[str, Any]]
def list_collectors(self) -> List[str]
def get_running_collectors(self) -> List[str]
def get_failed_collectors(self) -> List[str]
```

### CollectorConfig

Configuration dataclass for collectors:

```python
@dataclass
class CollectorConfig:
    name: str                               # Unique collector name
    exchange: str                           # Exchange name
    symbols: List[str]                      # Trading symbols
    data_types: List[str]                   # Data types to collect
    auto_restart: bool = True               # Enable auto-restart
    health_check_interval: float = 30.0    # Health check interval
    enabled: bool = True                    # Initially enabled
```

### Data Types

#### DataType Enum

```python
class DataType(Enum):
    TICKER = "ticker"        # Price and volume updates
    TRADE = "trade"          # Individual trade executions
    ORDERBOOK = "orderbook"  # Order book snapshots
    CANDLE = "candle"        # OHLCV candle data
    BALANCE = "balance"      # Account balance updates
```

#### MarketDataPoint

Standardized market data structure:

```python
@dataclass
class MarketDataPoint:
    exchange: str            # Exchange name
    symbol: str             # Trading symbol
    timestamp: datetime     # Data timestamp (UTC)
    data_type: DataType     # Type of data
    data: Dict[str, Any]    # Raw data payload
```

#### OHLCVData

OHLCV (candlestick) data structure with validation:

```python
@dataclass  
class OHLCVData:
    symbol: str                          # Trading symbol
    timeframe: str                       # Timeframe (1m, 5m, 1h, etc.)
    timestamp: datetime                  # Candle timestamp
    open: Decimal                        # Opening price
    high: Decimal                        # Highest price
    low: Decimal                         # Lowest price
    close: Decimal                       # Closing price
    volume: Decimal                      # Trading volume
    trades_count: Optional[int] = None   # Number of trades
```

## Health Monitoring

### Monitoring Levels

The system provides multi-level health monitoring:

1. **Individual Collector Health**
   - Heartbeat monitoring (message loop activity)
   - Data freshness (time since last data received)
   - Connection state monitoring
   - Error rate tracking

2. **Manager-Level Health**
   - Global health checks across all collectors
   - Coordinated restart management
   - System-wide performance metrics
   - Resource utilization monitoring

### Health Check Intervals

- **Individual Collector**: Configurable per collector (default: 30s)
- **Global Manager**: Configurable for manager (default: 60s)
- **Heartbeat Updates**: Updated with each message loop iteration
- **Data Freshness**: Updated when data is received

### Auto-Restart Triggers

Collectors are automatically restarted when:

1. **No Heartbeat**: Message loop becomes unresponsive
2. **Stale Data**: No data received within configured timeout
3. **Connection Failures**: WebSocket or API connection lost
4. **Error Status**: Collector enters ERROR or UNHEALTHY state
5. **Manual Trigger**: Explicit restart request

### Failure Handling

```python
# Configure failure handling with conditional logging
from utils.logger import get_logger

logger = get_logger('my_collector', verbose=True)

collector = MyCollector(
    symbols=["BTC-USDT"],
    auto_restart=True,                    # Enable auto-restart
    health_check_interval=30.0,           # Check every 30 seconds
    logger=logger,                        # Enable logging
    log_errors_only=False                 # Log all levels
)

# The collector will automatically:
# 1. Detect failures within 30 seconds
# 2. Attempt reconnection with exponential backoff
# 3. Restart up to 5 times (configurable)
# 4. Log all recovery attempts (if logger provided)
# 5. Report status to manager
```

## Configuration

### Environment Variables

The system respects these environment variables:

```bash
# Logging configuration (see logging.md for details)
VERBOSE_LOGGING=true              # Enable console logging
LOG_TO_CONSOLE=true               # Alternative verbose setting

# Health monitoring
DEFAULT_HEALTH_CHECK_INTERVAL=30  # Default health check interval (seconds)
MAX_SILENCE_DURATION=300          # Max time without data (seconds)
MAX_RECONNECT_ATTEMPTS=5          # Maximum reconnection attempts
RECONNECT_DELAY=5                 # Delay between reconnect attempts (seconds)
```

### Programmatic Configuration

```python
from utils.logger import get_logger

# Configure individual collector with conditional logging
logger = get_logger('custom_collector', verbose=True)

collector = MyCollector(
    exchange_name="custom_exchange",
    symbols=["BTC-USDT", "ETH-USDT"],
    data_types=[DataType.TICKER, DataType.TRADE],
    auto_restart=True,
    health_check_interval=15.0,       # Check every 15 seconds
    logger=logger,                    # Enable logging
    log_errors_only=False             # Log all message types
)

# Configure manager with conditional logging
manager_logger = get_logger('production_manager', verbose=False)
manager = CollectorManager(
    manager_name="production_manager",
    global_health_check_interval=30.0,   # Global checks every 30s
    restart_delay=10.0,                   # 10s delay between restarts
    logger=manager_logger,                # Manager logging
    log_errors_only=True                  # Only log errors for manager
)

# Configure specific collector in manager
config = CollectorConfig(
    name="primary_okx",
    exchange="okx",
    symbols=["BTC-USDT", "ETH-USDT", "SOL-USDT"],
    data_types=["ticker", "trade", "orderbook"],
    auto_restart=True,
    health_check_interval=20.0,
    enabled=True
)

manager.add_collector(collector, config)
```

## Best Practices

### 1. Collector Implementation with Conditional Logging

```python
from utils.logger import get_logger
from data.base_collector import BaseDataCollector, DataType

class ProductionCollector(BaseDataCollector):
    def __init__(self, exchange_name: str, symbols: list, logger=None):
        super().__init__(
            exchange_name=exchange_name,
            symbols=symbols,
            data_types=[DataType.TICKER, DataType.TRADE],
            auto_restart=True,               # Always enable auto-restart
            health_check_interval=30.0,      # Reasonable interval
            logger=logger,                   # Pass logger for conditional logging
            log_errors_only=False            # Log all levels
        )
        
        # Connection management
        self.connection_pool = None
        self.rate_limiter = RateLimiter(100, 60)  # 100 requests per minute
        
        # Data validation
        self.data_validator = DataValidator()
        
        # Performance monitoring
        self.metrics = MetricsCollector()
    
    async def connect(self) -> bool:
        """Implement robust connection logic."""
        try:
            self._log_info("Establishing connection to exchange")
            
            # Use connection pooling for reliability
            self.connection_pool = await create_connection_pool(
                self.exchange_name,
                max_connections=5,
                retry_attempts=3
            )
            
            # Test connection
            await self.connection_pool.ping()
            self._log_info("Connection established successfully")
            return True
            
        except Exception as e:
            self._log_error(f"Connection failed: {e}", exc_info=True)
            return False
    
    async def _process_message(self, message) -> Optional[MarketDataPoint]:
        """Implement thorough data processing."""
        try:
            # Rate limiting
            await self.rate_limiter.acquire()
            
            # Data validation
            if not self.data_validator.validate(message):
                self._log_warning(f"Invalid message format received")
                return None
            
            # Metrics collection
            self.metrics.increment('messages_processed')
            
            # Log detailed processing (only if not errors-only)
            self._log_debug(f"Processing message for {message.get('symbol', 'unknown')}")
            
            # Create standardized data point
            data_point = MarketDataPoint(
                exchange=self.exchange_name,
                symbol=message['symbol'],
                timestamp=self._parse_timestamp(message['timestamp']),
                data_type=DataType.TICKER,
                data=self._normalize_data(message)
            )
            
            self._log_debug(f"Successfully processed data point for {data_point.symbol}")
            return data_point
            
        except Exception as e:
            self.metrics.increment('processing_errors')
            self._log_error(f"Message processing failed: {e}", exc_info=True)
            raise  # Let health monitor handle it
```

### 2. Error Handling

```python
# Implement proper error handling with conditional logging
class RobustCollector(BaseDataCollector):
    async def _handle_messages(self) -> None:
        """Handle messages with proper error management."""
        try:
            # Check connection health
            if not await self._check_connection_health():
                raise ConnectionError("Connection health check failed")
            
            # Receive message with timeout
            message = await asyncio.wait_for(
                self.websocket.receive(),
                timeout=30.0  # 30 second timeout
            )
            
            # Process message
            data_point = await self._process_message(message)
            if data_point:
                await self._notify_callbacks(data_point)
                
        except asyncio.TimeoutError:
            # No data received - let health monitor handle
            self._log_warning("Message receive timeout")
            raise ConnectionError("Message receive timeout")
            
        except WebSocketError as e:
            # WebSocket specific errors
            self._log_error(f"WebSocket error: {e}")
            raise ConnectionError(f"WebSocket failed: {e}")
            
        except ValidationError as e:
            # Data validation errors - don't restart for these
            self._log_warning(f"Data validation failed: {e}")
            # Continue without raising - these are data issues, not connection issues
            
        except Exception as e:
            # Unexpected errors - trigger restart
            self._log_error(f"Unexpected error in message handling: {e}", exc_info=True)
            raise
```

### 3. Manager Setup with Hierarchical Logging

```python
from utils.logger import get_logger

async def setup_production_system():
    """Setup production collector system with conditional logging."""
    
    # Create manager with its own logger
    manager_logger = get_logger('crypto_trading_system', verbose=True)
    manager = CollectorManager(
        manager_name="crypto_trading_system",
        global_health_check_interval=60.0,    # Check every minute
        restart_delay=30.0,                    # 30s between restarts
        logger=manager_logger,                 # Manager logging
        log_errors_only=False                  # Log all levels for manager
    )
    
    # Add primary data sources with individual loggers
    exchanges = ['okx', 'binance', 'coinbase']
    symbols = ['BTC-USDT', 'ETH-USDT', 'SOL-USDT', 'AVAX-USDT']
    
    for exchange in exchanges:
        # Create individual logger for each exchange
        exchange_logger = get_logger(f'{exchange}_collector', verbose=True)
        
        collector = create_collector(
            exchange, 
            symbols, 
            logger=exchange_logger  # Individual collector logging
        )
        
        # Configure for production
        config = CollectorConfig(
            name=f"{exchange}_primary",
            exchange=exchange,
            symbols=symbols,
            data_types=["ticker", "trade"],
            auto_restart=True,
            health_check_interval=30.0,
            enabled=True
        )
        
        # Add callbacks for data processing
        collector.add_data_callback(DataType.TICKER, process_ticker_data)
        collector.add_data_callback(DataType.TRADE, process_trade_data)
        
        manager.add_collector(collector, config)
    
    # Start system
    success = await manager.start()
    if not success:
        raise RuntimeError("Failed to start collector system")
    
    return manager

# Usage
async def main():
    manager = await setup_production_system()
    
    # Monitor system health
    while True:
        status = manager.get_status()
        
        if status['statistics']['failed_collectors'] > 0:
            # Alert on failures
            await send_alert(f"Collectors failed: {manager.get_failed_collectors()}")
        
        # Log status every 5 minutes (if manager has logging enabled)
        await asyncio.sleep(300)
```

### 4. Monitoring Integration

```python
# Integrate with monitoring systems and conditional logging
import prometheus_client
from utils.logger import get_logger

class MonitoredCollector(BaseDataCollector):
    def __init__(self, *args, **kwargs):
        # Extract logger before passing to parent
        logger = kwargs.get('logger')
        super().__init__(*args, **kwargs)
        
        # Prometheus metrics
        self.messages_counter = prometheus_client.Counter(
            'collector_messages_total',
            'Total messages processed',
            ['exchange', 'symbol', 'type']
        )
        
        self.errors_counter = prometheus_client.Counter(
            'collector_errors_total', 
            'Total errors',
            ['exchange', 'error_type']
        )
        
        self.uptime_gauge = prometheus_client.Gauge(
            'collector_uptime_seconds',
            'Collector uptime',
            ['exchange']
        )
    
    async def _notify_callbacks(self, data_point: MarketDataPoint):
        """Override to add metrics."""
        # Update metrics
        self.messages_counter.labels(
            exchange=data_point.exchange,
            symbol=data_point.symbol,
            type=data_point.data_type.value
        ).inc()
        
        # Update uptime
        status = self.get_status()
        if status['statistics']['uptime_seconds']:
            self.uptime_gauge.labels(
                exchange=self.exchange_name
            ).set(status['statistics']['uptime_seconds'])
        
        # Log metrics update (only if debug logging enabled)
        self._log_debug(f"Updated metrics for {data_point.symbol}")
        
        # Call parent
        await super()._notify_callbacks(data_point)
    
    async def _handle_connection_error(self) -> bool:
        """Override to add error metrics."""
        self.errors_counter.labels(
            exchange=self.exchange_name,
            error_type='connection'
        ).inc()
        
        # Always log connection errors
        self._log_error("Connection error occurred")
        
        return await super()._handle_connection_error()
```

## Troubleshooting

### Common Issues

#### 1. Collector Won't Start

**Symptoms**: `start()` returns `False`, status shows `ERROR`

**Solutions**:
```python
# Check connection details with debugging
from utils.logger import get_logger

debug_logger = get_logger('debug_collector', verbose=True)
collector = MyCollector(symbols=["BTC-USDT"], logger=debug_logger)

success = await collector.start()
if not success:
    status = collector.get_status()
    print(f"Error: {status['statistics']['last_error']}")
    
# Common fixes:
# - Verify API credentials
# - Check network connectivity  
# - Validate symbol names
# - Review exchange-specific requirements
```

#### 2. Frequent Restarts

**Symptoms**: High restart count, intermittent data

**Solutions**:
```python
# Adjust health check intervals and enable detailed logging
logger = get_logger('troubleshoot_collector', verbose=True)

collector = MyCollector(
    symbols=["BTC-USDT"],
    health_check_interval=60.0,  # Increase interval
    auto_restart=True,
    logger=logger,               # Enable detailed logging
    log_errors_only=False        # Log all message types
)

# Check for:
# - Network instability
# - Exchange rate limiting
# - Invalid message formats
# - Resource constraints
```

#### 3. No Data Received

**Symptoms**: Collector running but no callbacks triggered

**Solutions**:
```python
# Check data flow with debug logging
logger = get_logger('data_debug', verbose=True)
collector = MyCollector(symbols=["BTC-USDT"], logger=logger)

def debug_callback(data_point):
    print(f"Received: {data_point}")

collector.add_data_callback(DataType.TICKER, debug_callback)

# Verify:
# - Callback registration
# - Symbol subscription
# - Message parsing logic
# - Exchange data availability
```

#### 4. Memory Leaks

**Symptoms**: Increasing memory usage over time

**Solutions**:
```python
# Implement proper cleanup with logging
class CleanCollector(BaseDataCollector):
    async def disconnect(self):
        """Ensure proper cleanup."""
        self._log_info("Starting cleanup process")
        
        # Clear buffers
        if hasattr(self, 'message_buffer'):
            self.message_buffer.clear()
            self._log_debug("Cleared message buffer")
        
        # Close connections
        if self.websocket:
            await self.websocket.close()
            self.websocket = None
            self._log_debug("Closed WebSocket connection")
        
        # Clear callbacks
        for callback_list in self._data_callbacks.values():
            callback_list.clear()
        self._log_debug("Cleared callbacks")
        
        await super().disconnect()
        self._log_info("Cleanup completed")
```

## Exchange Factory System

### Overview

The Exchange Factory system provides a standardized way to create data collectors for different exchanges. It implements the factory pattern to abstract the creation logic and provides a consistent interface across all exchanges.

### Exchange Registry

The system maintains a registry of supported exchanges and their capabilities:

```python
from data.exchanges import get_supported_exchanges, get_exchange_info

# Get all supported exchanges
exchanges = get_supported_exchanges()
print(f"Supported exchanges: {exchanges}")  # ['okx']

# Get exchange information
okx_info = get_exchange_info('okx')
print(f"OKX pairs: {okx_info['supported_pairs']}")
print(f"OKX data types: {okx_info['supported_data_types']}")
```

### Factory Configuration

```python
from data.exchanges import ExchangeCollectorConfig, ExchangeFactory
from data.base_collector import DataType
from utils.logger import get_logger

# Create configuration with conditional logging
logger = get_logger('factory_collector', verbose=True)

config = ExchangeCollectorConfig(
    exchange='okx',                                    # Exchange name
    symbol='BTC-USDT',                                # Trading pair
    data_types=[DataType.TRADE, DataType.ORDERBOOK],  # Data types
    auto_restart=True,                                # Auto-restart on failures
    health_check_interval=30.0,                       # Health check interval
    store_raw_data=True,                              # Store raw data for debugging
    custom_params={                                   # Exchange-specific parameters
        'ping_interval': 25.0,
        'max_reconnect_attempts': 5
    }
)

# Validate configuration
is_valid = ExchangeFactory.validate_config(config)
if is_valid:
    collector = ExchangeFactory.create_collector(config, logger=logger)
```

### Exchange Capabilities

Query what each exchange supports:

```python
from data.exchanges import ExchangeFactory

# Get supported trading pairs
okx_pairs = ExchangeFactory.get_supported_pairs('okx')
print(f"OKX supports: {okx_pairs}")

# Get supported data types  
okx_data_types = ExchangeFactory.get_supported_data_types('okx')
print(f"OKX data types: {okx_data_types}")
```

### Convenience Functions

Each exchange provides convenience functions for easy collector creation:

```python
from data.exchanges import create_okx_collector
from utils.logger import get_logger

# Quick OKX collector creation with logging
logger = get_logger('okx_btc_usdt', verbose=True)

collector = create_okx_collector(
    symbol='BTC-USDT',
    data_types=[DataType.TRADE, DataType.ORDERBOOK],
    auto_restart=True,
    logger=logger
)
```

## OKX Implementation

### OKX Collector Features

The OKX collector provides:

- **Real-time Data**: Live trades, orderbook, and ticker data
- **Single Pair Focus**: Each collector handles one trading pair for better isolation
- **Ping/Pong Management**: OKX-specific keepalive mechanism with proper format
- **Raw Data Storage**: Optional storage of raw OKX messages for debugging
- **Connection Resilience**: Robust reconnection logic for OKX WebSocket
- **Conditional Logging**: Full integration with the logging system

### OKX Usage Examples

```python
from utils.logger import get_logger

# Direct OKX collector usage with conditional logging
logger = get_logger('okx_collector', verbose=True)

collector = OKXCollector(
    symbol='BTC-USDT',
    data_types=[DataType.TRADE, DataType.ORDERBOOK],
    auto_restart=True,
    health_check_interval=30.0,
    store_raw_data=True,
    logger=logger,              # Enable logging
    log_errors_only=False       # Log all levels
)

# Factory pattern usage with error-only logging
error_logger = get_logger('okx_critical', verbose=False)

collector = create_okx_collector(
    symbol='BTC-USDT',
    data_types=[DataType.TRADE, DataType.ORDERBOOK],
    logger=error_logger,
    log_errors_only=True        # Only log errors
)

# Multiple collectors with different logging strategies
configs = [
    ExchangeCollectorConfig('okx', 'BTC-USDT', [DataType.TRADE]),
    ExchangeCollectorConfig('okx', 'ETH-USDT', [DataType.ORDERBOOK])
]

collectors = []
for config in configs:
    # Different logging for each collector
    if config.symbol == 'BTC-USDT':
        logger = get_logger('okx_btc', verbose=True)  # Full logging
    else:
        logger = get_logger('okx_eth', verbose=False, log_errors_only=True)  # Errors only
    
    collector = ExchangeFactory.create_collector(config, logger=logger)
    collectors.append(collector)
```

### OKX Data Processing

The OKX collector processes three main data types:

#### Trade Data
```python
# OKX trade message format
{
    "arg": {"channel": "trades", "instId": "BTC-USDT"},
    "data": [{
        "tradeId": "12345678",
        "px": "50000.5",      # Price
        "sz": "0.001",        # Size
        "side": "buy",        # Side (buy/sell)
        "ts": "1697123456789" # Timestamp (ms)
    }]
}
```

#### Orderbook Data
```python
# OKX orderbook message format (books5)
{
    "arg": {"channel": "books5", "instId": "BTC-USDT"},
    "data": [{
        "asks": [["50001.0", "0.5", "0", "3"]],  # [price, size, liquidated, orders]
        "bids": [["50000.0", "0.8", "0", "2"]],
        "ts": "1697123456789"
    }]
}
```

#### Ticker Data
```python
# OKX ticker message format
{
    "arg": {"channel": "tickers", "instId": "BTC-USDT"},
    "data": [{
        "last": "50000.5",      # Last price
        "askPx": "50001.0",     # Best ask price
        "bidPx": "50000.0",     # Best bid price
        "open24h": "49500.0",   # 24h open
        "high24h": "50500.0",   # 24h high
        "low24h": "49000.0",    # 24h low
        "vol24h": "1234.567",   # 24h volume
        "ts": "1697123456789"
    }]
}
```

For comprehensive OKX documentation, see [OKX Collector Documentation](okx_collector.md).

## Integration Examples

### Django Integration

```python
# Django management command with conditional logging
from django.core.management.base import BaseCommand
from data import CollectorManager
from utils.logger import get_logger
import asyncio

class Command(BaseCommand):
    help = 'Start crypto data collectors'
    
    def handle(self, *args, **options):
        async def run_collectors():
            # Create manager with logging
            manager_logger = get_logger('django_collectors', verbose=True)
            manager = CollectorManager("django_collectors", logger=manager_logger)
            
            # Add collectors with individual loggers
            from myapp.collectors import OKXCollector, BinanceCollector
            
            okx_logger = get_logger('django_okx', verbose=True)
            binance_logger = get_logger('django_binance', verbose=True, log_errors_only=True)
            
            manager.add_collector(OKXCollector(['BTC-USDT'], logger=okx_logger))
            manager.add_collector(BinanceCollector(['ETH-USDT'], logger=binance_logger))
            
            # Start system
            await manager.start()
            
            # Keep running
            try:
                while True:
                    await asyncio.sleep(60)
                    status = manager.get_status()
                    self.stdout.write(f"Status: {status['statistics']}")
            except KeyboardInterrupt:
                await manager.stop()
        
        asyncio.run(run_collectors())
```

### FastAPI Integration

```python
# FastAPI application with conditional logging
from fastapi import FastAPI
from data import CollectorManager
from utils.logger import get_logger
import asyncio

app = FastAPI()
manager = None

@app.on_event("startup")
async def startup_event():
    global manager
    
    # Create manager with logging
    manager_logger = get_logger('fastapi_collectors', verbose=True)
    manager = CollectorManager("fastapi_collectors", logger=manager_logger)
    
    # Add collectors with error-only logging for production
    from collectors import OKXCollector
    
    collector_logger = get_logger('fastapi_okx', verbose=False, log_errors_only=True)
    collector = OKXCollector(['BTC-USDT', 'ETH-USDT'], logger=collector_logger)
    manager.add_collector(collector)
    
    # Start in background
    await manager.start()

@app.on_event("shutdown")
async def shutdown_event():
    global manager
    if manager:
        await manager.stop()

@app.get("/collector/status")
async def get_collector_status():
    return manager.get_status()

@app.post("/collector/{name}/restart")
async def restart_collector(name: str):
    success = await manager.restart_collector(name)
    return {"success": success}
```

## Migration Guide

### From Manual Connection Management

**Before** (manual management):
```python
class OldCollector:
    def __init__(self):
        self.websocket = None
        self.running = False
    
    async def start(self):
        while self.running:
            try:
                self.websocket = await connect()
                await self.listen()
            except Exception as e:
                print(f"Error: {e}")
                await asyncio.sleep(5)  # Manual retry
```

**After** (with BaseDataCollector and conditional logging):
```python
from utils.logger import get_logger

class NewCollector(BaseDataCollector):
    def __init__(self):
        logger = get_logger('new_collector', verbose=True)
        super().__init__(
            "exchange", 
            ["BTC-USDT"], 
            logger=logger,
            log_errors_only=False
        )
        # Auto-restart and health monitoring included
    
    async def connect(self) -> bool:
        self._log_info("Connecting to exchange")
        self.websocket = await connect()
        self._log_info("Connection established")
        return True
    
    async def _handle_messages(self):
        message = await self.websocket.receive()
        self._log_debug(f"Received message: {message}")
        # Error handling and restart logic automatic
```

### From Basic Monitoring

**Before** (basic monitoring):
```python
# Manual status tracking
status = {
    'connected': False,
    'last_message': None,
    'error_count': 0
}

# Manual health checks
async def health_check():
    if time.time() - status['last_message'] > 300:
        print("No data for 5 minutes!")
```

**After** (comprehensive monitoring with conditional logging):
```python
# Automatic health monitoring with logging
logger = get_logger('monitored_collector', verbose=True)
collector = MyCollector(["BTC-USDT"], logger=logger)

# Rich status information
status = collector.get_status()
health = collector.get_health_status()

# Automatic alerts and recovery with logging
if not health['is_healthy']:
    print(f"Issues: {health['issues']}")
    # Auto-restart already triggered and logged
```

## Related Documentation

- [Data Collection Service](../services/data_collection_service.md) - High-level service orchestration
- [Logging System](logging.md) - Conditional logging implementation  
- [Database Operations](../database/operations.md) - Database integration patterns
- [Monitoring Guide](../monitoring/README.md) - System monitoring and alerting

---

## Support and Contributing

### Getting Help

1. **Check Logs**: Review logs in `./logs/` directory (see [Logging System](logging.md))
2. **Status Information**: Use `get_status()` and `get_health_status()` methods
3. **Debug Mode**: Enable debug logging with conditional logging system
4. **Test with Demo**: Run `examples/collector_demo.py` to verify setup

### Contributing

The data collector system is designed to be extensible. Contributions are welcome for:

- New exchange implementations
- Enhanced monitoring features
- Performance optimizations
- Additional data types
- Integration examples
- Logging system improvements

### License

This documentation and the associated code are part of the Crypto Trading Bot Platform project.

---

*For more information, see the main project documentation in `/docs/`.*