* Add LabelSelector to PersistentVolumeClaimSpec ([#25917](https://github.com/kubernetes/kubernetes/pull/25917), [@pmorie](https://github.com/pmorie))
* Removed metrics api group ([#26073](https://github.com/kubernetes/kubernetes/pull/26073), [@piosz](https://github.com/piosz))

    private boolean isValidNotificationSource(WitnessNotification notification) {
        // Validate notification signature/source
        return true;  // Simplified
    }
}
```

## 11. Monitoring and Metrics

### 11.1 Witness Statistics
```java
public class WitnessStatistics {
    private final AtomicLong registrationsActive = new AtomicLong();
    private final AtomicLong notificationsReceived = new AtomicLong();

		}
		return
	}
	defer gr.Close()

	objInfo := gr.ObjInfo

	// make sure we have the latest metadata for metrics calculation
	rinfo.PrevReplicationStatus = objInfo.TargetReplicationStatus(tgt.ARN)

	// Set the encrypted size for SSE-C objects
	var size int64
	if crypto.SSEC.IsEncrypted(objInfo.UserDefined) {

		}
	}
}

type expiryTask struct {
	objInfo ObjectInfo
	event   lifecycle.Event
	src     lcEventSrc
}

// expiryStats records metrics related to ILM expiry activities
type expiryStats struct {
	missedExpiryTasks      atomic.Int64
	missedFreeVersTasks    atomic.Int64
	missedTierJournalTasks atomic.Int64
	workers                atomic.Int32
}

        byte[] encrypted2 = assertDoesNotThrow(() -> context.encryptMessage(largeMessage, 2L));
        assertNotNull(encrypted2);

        // Verify rotation occurred by checking metrics
        assertTrue(context.getKeyRotationCount() > 0, "Key rotation should have occurred");

        // Can still encrypt after rotation
        byte[] plaintext3 = "Message after rotation".getBytes();

			return
		}
		if err = actualReader.AddChecksum(r, false); err != nil {
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)
			return
		}

		// Set compression metrics.
		wantEncryption := crypto.Requested(r.Header)
		s2c, cb := newS2CompressReader(actualReader, actualSize, wantEncryption)
		idxCb = cb
		defer s2c.Close()
		reader = etag.Wrap(s2c, actualReader)

		}

		// Initialize batch job pool.
		bootstrapTrace("newBatchJobPool", func() {
			globalBatchJobPool = newBatchJobPool(GlobalContext, newObject, 100)
			globalBatchJobsMetrics = batchJobMetrics{
				metrics: make(map[string]*batchJobInfo),
			}
			go globalBatchJobsMetrics.init(GlobalContext, newObject)
			go globalBatchJobsMetrics.purgeJobMetrics()
		})

	// This is to avoid too small costly sleeps.
	minSleep time.Duration

	// cycle will be closed
	cycle chan struct{}

	// isScanner should be set when this is used by the scanner
	// to record metrics.
	isScanner bool
}

// newDynamicSleeper
func newDynamicSleeper(factor float64, maxWait time.Duration, isScanner bool) *dynamicSleeper {
	return &dynamicSleeper{
		factor:    factor,

			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)
			return
		}
		opts.WantChecksum = actualReader.Checksum()

		// Set compression metrics.
		var s2c io.ReadCloser
		wantEncryption := crypto.Requested(r.Header)
		s2c, idxCb = newS2CompressReader(actualReader, actualSize, wantEncryption)
		defer s2c.Close()

		reader = etag.Wrap(s2c, actualReader)

)

const (
	maxSVCSessionPolicySize = 4096
)

// IAMSys - config system.
type IAMSys struct {
	// Need to keep them here to keep alignment - ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
	// metrics
	LastRefreshTimeUnixNano         uint64
	LastRefreshDurationMilliseconds uint64
	TotalRefreshSuccesses           uint64
	TotalRefreshFailures            uint64

	sync.Mutex

	iamRefreshInterval time.Duration