basic

Basic CQL Examples

Welcome to the basic CQL examples! These simple, focused examples are perfect for getting started with CQL's caching system. Each example demonstrates core concepts without complex dependencies.

📝 Examples Overview

🎯 simple_cache_demo.cr

Purpose: Comprehensive demonstration of CQL's advanced caching features Features:

• Basic memory cache operations (set/get/delete/exists)
• TTL (Time To Live) demonstration
• Tag-based cache invalidation
• Fragment caching with performance measurement
• Version-based invalidation
• Transaction-aware invalidation
• LRU eviction policies
• Cache statistics and performance monitoring

Run: crystal simple_cache_demo.cr

🔧 simple_caching_demo.cr

Purpose: Focused demonstration of core caching concepts Features:

• Memory cache basics
• Tag-based invalidation patterns
• Fragment caching with custom keys
• Version and transaction-aware invalidation
• Cache key building
• Performance statistics

Run: crystal simple_caching_demo.cr

🔴 simple_redis_demo.cr

Purpose: Basic Redis cache integration Features:

• Environment-based Redis configuration
• Basic Redis operations
• Cache with block execution
• Memory vs Redis performance comparison
• Batch operations
• Cache statistics

Run: crystal simple_redis_demo.cr Prerequisites: Redis server running on localhost:6379

🚀 Getting Started

1. Start with the Basic Cache Demo

crystal simple_cache_demo.cr

This provides a comprehensive overview of all caching features.

2. Explore Specific Concepts

crystal simple_caching_demo.cr

Focuses on core caching patterns and strategies.

3. Try Redis Integration

# Start Redis server first
redis-server

# Then run the Redis demo
crystal simple_redis_demo.cr

🎓 Learning Path

Beginners

1. simple_cache_demo.cr - Start here for a complete overview
2. simple_caching_demo.cr - Dive deeper into specific patterns
3. simple_redis_demo.cr - Learn Redis integration

Key Concepts Covered

• Memory Caching - In-memory storage for fast access
• TTL Management - Automatic expiration of cached data
• Tag-based Invalidation - Group and invalidate related cache entries
• Fragment Caching - Cache expensive computations and blocks
• LRU Eviction - Automatic cleanup when cache is full
• Performance Monitoring - Track cache hit rates and efficiency

💡 Tips for Beginners

1. Start Simple: Run simple_cache_demo.cr first to see all features in action
2. Read the Output: Each example provides detailed console output explaining what's happening
3. Modify and Experiment: Try changing cache sizes, TTL values, and see the effects
4. Check Statistics: Pay attention to cache hit rates and performance metrics

🔗 Next Steps

After mastering these basic examples, explore:

• ../caching/ - Advanced caching patterns and strategies
• ../blog/ - Real-world application with caching integration
• ../performance/ - Performance monitoring and optimization

🛠️ Troubleshooting

Common Issues

Redis Connection Errors:

# Make sure Redis is running
redis-server

# Test Redis connection
redis-cli ping

Missing Dependencies:

# Install required shards
shards install

Performance Issues:

• Check your system's available memory
• Monitor cache hit rates (aim for >80%)
• Adjust cache sizes based on your application needs

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Ready to dive into CQL caching? Start with simple_cache_demo.cr and work your way through each example! 🚀