private final AtomicLong cacheInvalidations = new AtomicLong();
    private final AtomicLong changeNotifications = new AtomicLong();
    
    public double getCacheHitRatio() {
        long hits = cacheHits.get();
        long misses = cacheMisses.get();
        long total = hits + misses;
        
        if (total == 0) return 0.0;
        return (double) hits / total;