Advanced Error Handling and Logging in Node.js Applications

Introduction

Error handling and logging are crucial aspects of building robust Node.js applications. As applications grow in complexity, having a solid error management strategy becomes essential for maintaining reliability and debugging issues effectively.

Understanding Error Types in Node.js

Node.js provides several built-in error types:

• Operational Errors (Network timeouts, file system issues)
• Programming Errors (TypeError, ReferenceError)
• System Errors (Out of memory, Stack overflow)

Creating Custom Error Classes

class DatabaseError extends Error {
  constructor(message, code) {
    super(message);
    this.name = 'DatabaseError';
    this.code = code;
  }
}

Implementing Global Error Handling

process.on('uncaughtException', (error) => {
  console.error('Uncaught Exception:', error);
  // Log to monitoring service
  process.exit(1);
});

process.on('unhandledRejection', (reason, promise) => {
  console.error('Unhandled Rejection:', reason);
  // Log error details
});

Advanced Logging Strategies

Setting Up Winston Logger

const winston = require('winston');

const logger = winston.createLogger({
  level: 'info',
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.json()
  ),
  transports: [
    new winston.transports.File({ filename: 'error.log', level: 'error' }),
    new winston.transports.File({ filename: 'combined.log' })
  ]
});

Best Practices for Production

1. Use error boundaries and middleware
2. Implement proper error categorization
3. Set up centralized error monitoring
4. Maintain detailed logging with context
5. Establish error recovery mechanisms

Monitoring and Alerting

• Set up real-time error notifications
• Track error patterns and frequencies
• Monitor application health metrics
• Implement automated recovery procedures

Conclusion

Implementing robust error handling and logging is essential for maintaining reliable Node.js applications. By following these practices, you can build more resilient systems and respond to issues more effectively.