File Metadata
Metadata to Store
@Entity
public class FileMetadata {
@Id @GeneratedValue
private Long id;
private String filename;
private String contentType;
private Long size;
private String storageKey; // S3 key
private String uploadedBy;
private LocalDateTime uploadedAt;
}
Store metadata in DB, file in object storage.
Key Points
- Understanding File Metadata is essential for production systems
- Always consider scalability and maintainability
- Test thoroughly before deploying to production
- Monitor performance and set up alerting
Common Patterns
- Validation: Always validate input at the boundary
- Error Handling: Use structured error responses
- Logging: Log key events for debugging
- Testing: Unit, integration, and load tests
- Documentation: Keep docs updated with code changes
Best Practices
Key Principles
- Follow SOLID principles
- Write clean, readable code
- Test thoroughly
- Document decisions
- Monitor in production
Implementation
- Start simple, refactor as needed
- Use established patterns
- Consider trade-offs
- Review with peers
Continuous Improvement
- Learn from incidents
- Update documentation
- Share knowledge
- Mentor others
Key Points
- Understanding File Metadata is essential for production systems
- Always consider scalability and maintainability
- Test thoroughly before deploying to production
- Monitor performance and set up alerting
Common Patterns
- Validation: Always validate input at the boundary
- Error Handling: Use structured error responses
- Logging: Log key events for debugging
- Testing: Unit, integration, and load tests
- Documentation: Keep docs updated with code changes
Practice Problems
Design and implement a solution for File Metadata in a backend system. Consider scalability, error handling, and production readiness.
Solution
// File Metadata implementation
// Key aspects: validation, error handling, logging, testing
public class FileMetadata {
// Production-ready implementation
}Identify and handle edge cases for File Metadata. What happens under high load, with invalid input, or during failures?
Solution
// Edge case handling:
// 1. Null/empty input -> validation
// 2. High load -> rate limiting, queuing
// 3. Failures -> retries, circuit breaker
// 4. Concurrent access -> locks, idempotencyWrite a testing strategy for File Metadata. Include unit tests, integration tests, and performance tests.
Solution
// Test plan:
// - Unit: 80% coverage target
// - Integration: API contracts
// - Performance: latency, throughput
// - Chaos: failure injectionQuiz
1. File metadata stored where?
2. storageKey is?
3. What is the primary purpose of File Metadata?
4. What is a common mistake when implementing File Metadata?
Flashcards
Question
Metadata storage?
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Answer
Database (file in S3/object storage)
Question
storageKey?
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Answer
S3 object key linking metadata to file
Question
What is File Metadata?
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Answer
File Metadata is a key concept in backend development.
Question
When to use File Metadata?
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Answer
Use File Metadata when building production systems that require reliability, scalability, and maintainability.
Question
File Metadata best practices
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Answer
Follow SOLID principles, write clean code, test thoroughly, document decisions, and monitor in production.
Revision Notes
Key Takeaways
- 1.Store metadata in DB, files in object storage
- 2.Track: filename, type, size, uploader, timestamp
- 3.storageKey links metadata to actual file
Interview Tips
- •Design metadata schema
- •Link metadata to storage
Cheat Sheet
File Metadata
- Store: DB (metadata) + S3 (file)
- Fields: filename, type, size, key, uploader, timestamp
- storageKey: links to S3 object