Tuning Caffeine In-Memory Cache Eviction Within Spring CacheManager

@Configuration
@EnableCaching
public class CacheConfig {
 
    @Bean
    public CacheManager cacheManager() {
        CaffeineCacheManager cacheManager = new CaffeineCacheManager("productMetrics", "fxRates");
        cacheManager.setCaffeine(Caffeine.newBuilder()
            .initialCapacity(100)
            .maximumSize(5_000)
            .expireAfterWrite(15, TimeUnit.MINUTES)
            .recordStats());
        return cacheManager;
    }
}
 
@Service
public class ProductService {
 
    @Cacheable(value = "productMetrics", key = "#sku", unless = "#result == null")
    public ProductMetrics fetchMetrics(String sku) {
        return heavyComputationFromExternalApi(sku);
    }
}