Caching Strategies
Cache-Aside (Most Common)
Check cache -> miss -> query DB -> write to cache
Write-Through
Write to cache + DB simultaneously
Cache Stampede
Problem: Many requests hit expired cache simultaneously
Solution: Mutex, early expiration, background refresh
Invalidation
- TTL: simplest
- Event-driven: most accurate
- Version-based: per key
Key Points
- Understanding Caching Questions 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
Caching Patterns
Redis vs Memcached
| Feature | Redis | Memcached |
|---|---|---|
| Structures | Rich | Strings only |
| Persistence | Yes | No |
| Replication | Yes | No |
Hit Ratio
Good: >80%, Excellent: >95%
When NOT to Cache
- Data changes frequently
- Data rarely accessed
- Strong consistency required
Key Points
- Understanding Caching Questions 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 Caching Questions in a backend system. Consider scalability, error handling, and production readiness.
Solution
// Caching Questions implementation
// Key aspects: validation, error handling, logging, testing
public class CachingQuestions {
// Production-ready implementation
}Identify and handle edge cases for Caching Questions. 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 Caching Questions. 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. What is cache stampede?
2. Best strategy for read-heavy?
3. What is the primary purpose of Caching Questions?
4. What is a common mistake when implementing Caching Questions?
Flashcards
Question
Main caching strategies?
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Answer
Cache-aside, Write-through, Write-behind, Read-through
Question
What is cache stampede?
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Answer
Many requests hit expired cache simultaneously
Question
What is Caching Questions?
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Answer
Caching Questions is a key concept in backend development.
Question
When to use Caching Questions?
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Answer
Use Caching Questions when building production systems that require reliability, scalability, and maintainability.
Question
Caching Questions 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.Cache-aside most common for reads
- 2.Stampede: use mutex or early expiration
- 3.TTL simplest, event-driven most accurate
- 4.Redis for complex, Memcached for simple
Interview Tips
- •Explain cache-aside flow step by step
- •Discuss invalidation tradeoffs
Cheat Sheet
Caching Interview
- Cache-Aside: Check cache -> miss -> DB -> cache
- Stampede: Mutex or early expiration
- Invalidation: TTL, event-driven, version-based