*   <li>values automatically wrapped in {@linkplain WeakReference weak} or {@linkplain
 *       SoftReference soft} references
 *   <li>notification of evicted (or otherwise removed) entries
 *   <li>accumulation of cache access statistics
 * </ul>
 *
 * <p>These features are all optional; caches can be created using all or none of them. By default,
 * cache instances created by {@code CacheBuilder} will not perform any type of eviction.
 *

        }
        
        // Fall back to direct server query
        return directory.performDirectEnumeration();
    }
}
```

## 10. Monitoring and Metrics

### 10.1 Directory Cache Statistics
```java
public class DirectoryCacheStatistics {
    private final AtomicLong cacheHits = new AtomicLong();
    private final AtomicLong cacheMisses = new AtomicLong();

    }

    /**
     * Get key rotation metrics
     *
     * @return metrics map containing rotation statistics
     */
    public java.util.Map<String, Long> getKeyRotationMetrics() {
        java.util.Map<String, Long> metrics = new java.util.HashMap<>();
        metrics.put("totalRotations", totalKeyRotations.get());

        
        // Wait for all reconnections
        CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();
    }
}
```

## 11. Monitoring and Metrics

### 11.1 Handle Statistics
```java
public class HandleStatistics {
    private final AtomicLong handlesRequested = new AtomicLong();
    private final AtomicLong handlesGranted = new AtomicLong();

		}
	}

	replicationStats = append(replicationStats, bucketStatsMap)
	return replicationStats
}

// GetClusterBucketStats - calls GetClusterBucketStats call on all peers for a cluster statistics view.
func (sys *NotificationSys) GetClusterBucketStats(ctx context.Context, bucketName string) []BucketStats {
	ng := WithNPeers(len(sys.peerClients)).WithRetries(1)
	bucketStats := make([]BucketStats, len(sys.peerClients))

	"github.com/minio/minio/internal/logger"
	"github.com/minio/pkg/v3/env"
	"github.com/minio/pkg/v3/workers"
)

//go:generate msgp -file $GOFILE -unexported

// rebalanceStats contains per-pool rebalance statistics like number of objects,
// versions and bytes rebalanced out of a pool
type rebalanceStats struct {
	InitFreeSpace uint64 `json:"initFreeSpace" msg:"ifs"` // Pool free space at the start of rebalance

}

func newMinioBucketCollector(metricsGroups []*MetricsGroupV2) *minioBucketCollector {
	return &minioBucketCollector{
		metricsGroups: metricsGroups,
		desc:          prometheus.NewDesc("minio_bucket_stats", "Statistics exposed by MinIO server cluster wide per bucket", nil, nil),
	}
}

// Describe sends the super-set of all possible descriptors of metrics
func (c *minioBucketCollector) Describe(ch chan<- *prometheus.Desc) {

    
    // Multi-channel should be faster
    assertTrue(multiChannelTime < singleChannelTime * 0.7);  // At least 30% improvement
}
```

## 8. Performance Metrics

### 8.1 Channel Statistics
```java
public class MultiChannelStatistics {
    private final Map<String, ChannelStatistics> channelStats;
    
    public class ChannelStatistics {

 *   <li>values automatically wrapped in {@linkplain WeakReference weak} or {@linkplain
 *       SoftReference soft} references
 *   <li>notification of evicted (or otherwise removed) entries
 *   <li>accumulation of cache access statistics
 * </ul>
 *
 * <p>These features are all optional; caches can be created using all or none of them. By default,
 * cache instances created by {@code CacheBuilder} will not perform any type of eviction.
 *

		if stmt.Schema != nil {
			if idx := stmt.Schema.LookIndex(name); idx != nil {
				name = idx.Name
			}
		}

		return m.DB.Raw(
			"SELECT count(*) FROM information_schema.statistics WHERE table_schema = ? AND table_name = ? AND index_name = ?",
			currentDatabase, stmt.Table, name,
		).Row().Scan(&count)
	})

	return count > 0
}

// RenameIndex rename index from oldName to newName