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Basic caching improves performance, but real-world systems require more advanced strategies to keep cached data accurate and efficient. Redis combined with Spring Boot allows you to implement flexible caching patterns such as cache-aside, TTL control, cache warming, and cache invalidation.
This guide explains practical strategies you can apply immediately.

1. Cache-Aside Pattern (Lazy Loading)

The cache-aside pattern is the most common caching strategy. The application checks the cache first, and if the data is not present, it loads it from the database and stores it in Redis.
Spring Boot simplifies this using @Cacheable.
@Cacheable(value = "products", key = "#id")
public Product getProduct(Long id) {
    return productRepository.findById(id).orElse(null);
}
Workflow:
  1. Application checks Redis.
  2. If data exists → return cached value.
  3. If not → query database.
  4. Store result in Redis.
This keeps the cache small and efficient.

2. Cache Invalidation

Cached data must be updated when the database changes.
Example:
@CacheEvict(value = "products", key = "#id")
public void deleteProduct(Long id) {
    productRepository.deleteById(id);
}
Or update cache when data changes:
@CachePut(value = "products", key = "#product.id")
public Product updateProduct(Product product) {
    return productRepository.save(product);
}
This prevents stale data in Redis.

3. Time-To-Live (TTL) Control

TTL automatically removes cached data after a specific time.
Example Redis configuration:
@Bean
public RedisCacheConfiguration cacheConfig() {
    return RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofMinutes(5));
}
This means cached entries expire after 5 minutes.
Benefits:
  • Prevents stale data
  • Frees memory automatically
  • Keeps cache fresh

4. Cache Warming

Cache warming loads frequently used data into Redis when the application starts.
Example:
@Component
public class CacheWarmup {
    @Autowired
    private ProductService productService;
    
    @EventListener(ApplicationReadyEvent.class)
    public void loadCache() {
        productService.getProduct(1L);
        productService.getProduct(2L);
        productService.getProduct(3L);
    }
}
This ensures popular data is already cached before users request it.

5. Avoid Cache Stampede

Cache stampede occurs when many requests hit the database at the same time after cache expiration.
One simple solution is randomized TTL.
Example:
long ttl = 300 + new Random().nextInt(120);
This spreads cache expiration across different times.
Another solution is using locking while rebuilding cache.

6. Use Redis for Distributed Caching

In microservices architecture, multiple instances may run the same service. Redis acts as a shared distributed cache.
Benefits:
  • All services share cached data
  • Consistent results across instances
  • Reduced database load

7. Monitoring Cache Performance

Monitor Redis usage to ensure the cache works efficiently.
Key metrics:
  • Cache hit rate
  • Cache miss rate
  • Memory usage
  • Eviction count
Spring Boot Actuator can expose metrics:
management.endpoints.web.exposure.include=health,metrics
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