HADOOP-14503. Make RollingAverages a mutable metric. Contributed by Hanisha Koneru.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MetricsRegistry.java

@@ -313,6 +313,15 @@ public synchronized MutableRatesWithAggregation newRatesWithAggregation(
     return rates;
   }
 
+  public synchronized MutableRollingAverages newMutableRollingAverages(
+      String name, String valueName) {
+    checkMetricName(name);
+    MutableRollingAverages rollingAverages =
+        new MutableRollingAverages(valueName);
+    metricsMap.put(name, rollingAverages);
+    return rollingAverages;
+  }
+
   synchronized void add(String name, MutableMetric metric) {
     checkMetricName(name);
     metricsMap.put(name, metric);

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableMetricsFactory.java

@@ -78,6 +78,10 @@ MutableMetric newForField(Field field, Metric annotation,
                               annotation.sampleName(), annotation.valueName(),
                               annotation.always());
     }
+    if (cls == MutableRollingAverages.class) {
+      return registry.newMutableRollingAverages(info.name(),
+          annotation.valueName());
+    }
     throw new MetricsException("Unsupported metric field "+ field.getName() +
                                " of type "+ field.getType().getName());
   }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableRollingAverages.java

@@ -31,6 +31,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 
+import com.google.common.annotations.VisibleForTesting;
 import org.apache.commons.lang.StringUtils;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
@@ -57,29 +58,30 @@
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
-public class RollingAverages extends MutableMetric implements Closeable {
+public class MutableRollingAverages extends MutableMetric implements Closeable {
 
-  private final MutableRatesWithAggregation innerMetrics =
+  private MutableRatesWithAggregation innerMetrics =
       new MutableRatesWithAggregation();
 
-  private static final ScheduledExecutorService SCHEDULER = Executors
+  @VisibleForTesting
+  static final ScheduledExecutorService SCHEDULER = Executors
       .newScheduledThreadPool(1, new ThreadFactoryBuilder().setDaemon(true)
-          .setNameFormat("RollingAverages-%d").build());
+          .setNameFormat("MutableRollingAverages-%d").build());
 
   private ScheduledFuture<?> scheduledTask = null;
 
   @Nullable
   private Map<String, MutableRate> currentSnapshot;
 
-  private final int numWindows;
   private final String avgInfoNameTemplate;
   private final String avgInfoDescTemplate;
+  private int numWindows;
 
   private static class SumAndCount {
     private final double sum;
     private final long count;
 
-    public SumAndCount(final double sum, final long count) {
+    SumAndCount(final double sum, final long count) {
       this.sum = sum;
       this.count = count;
     }
@@ -105,44 +107,36 @@ public long getCount() {
   private Map<String, LinkedBlockingDeque<SumAndCount>> averages =
       new ConcurrentHashMap<>();
 
+  private static final long WINDOW_SIZE_MS_DEFAULT = 300_000;
+  private static final int NUM_WINDOWS_DEFAULT = 36;
+
   /**
-   * Constructor of {@link RollingAverages}.
+   * Constructor for {@link MutableRollingAverages}.
-   * @param windowSizeMs
+   * @param metricValueName
-   *          The number of milliseconds of each window for which subset
-   *          of samples are gathered to compute the rolling average, A.K.A.
-   *          roll over interval.
-   * @param numWindows
-   *          The number of windows maintained to compute the rolling average.
-   * @param valueName
-   *          of the metric (e.g. "Time", "Latency")
    */
-  public RollingAverages(
+  public MutableRollingAverages(String metricValueName) {
-      final long windowSizeMs,
+    if (metricValueName == null) {
-      final int numWindows,
+      metricValueName = "";
-      final String valueName) {
+    }
-    String uvName = StringUtils.capitalize(valueName);
+    avgInfoNameTemplate = "[%s]" + "RollingAvg" +
-    String lvName = StringUtils.uncapitalize(valueName);
+        StringUtils.capitalize(metricValueName);
-    avgInfoNameTemplate = "[%s]" + "RollingAvg"+ uvName;
+    avgInfoDescTemplate = "Rolling average " +
-    avgInfoDescTemplate = "Rolling average "+ lvName +" for "+ "%s";
+        StringUtils.uncapitalize(metricValueName) +" for "+ "%s";
-    this.numWindows = numWindows;
+    numWindows = NUM_WINDOWS_DEFAULT;
     scheduledTask = SCHEDULER.scheduleAtFixedRate(new RatesRoller(this),
-        windowSizeMs, windowSizeMs, TimeUnit.MILLISECONDS);
+        WINDOW_SIZE_MS_DEFAULT, WINDOW_SIZE_MS_DEFAULT, TimeUnit.MILLISECONDS);
   }
 
   /**
-   * Constructor of {@link RollingAverages}.
+   * This method is for testing only to replace the scheduledTask.
-   * @param windowSizeMs
-   *          The number of seconds of each window for which sub set of samples
-   *          are gathered to compute rolling average, also A.K.A roll over
-   *          interval.
-   * @param numWindows
-   *          The number of windows maintained in the same time to compute the
-   *          average of the rolling averages.
    */
-  public RollingAverages(
+  @VisibleForTesting
-      final long windowSizeMs,
+  synchronized void replaceScheduledTask(int windows, long interval,
-      final int numWindows) {
+                                         TimeUnit timeUnit) {
-    this(windowSizeMs, numWindows, "Time");
+    numWindows = windows;
+    scheduledTask.cancel(true);
+    scheduledTask = SCHEDULER.scheduleAtFixedRate(new RatesRoller(this),
+        interval, interval, timeUnit);
   }
 
   @Override
@@ -190,9 +184,9 @@ public void add(final String name, final long value) {
   }
 
   private static class RatesRoller implements Runnable {
-    private final RollingAverages parent;
+    private final MutableRollingAverages parent;
 
-    public RatesRoller(final RollingAverages parent) {
+    RatesRoller(final MutableRollingAverages parent) {
       this.parent = parent;
     }
 
@@ -218,7 +212,7 @@ public void run() {
 
   /**
    * Iterates over snapshot to capture all Avg metrics into rolling structure
-   * {@link RollingAverages#averages}.
+   * {@link MutableRollingAverages#averages}.
    */
   private synchronized void rollOverAvgs() {
     if (currentSnapshot == null) {
@@ -232,7 +226,7 @@ private synchronized void rollOverAvgs() {
           new Function<String, LinkedBlockingDeque<SumAndCount>>() {
             @Override
             public LinkedBlockingDeque<SumAndCount> apply(String k) {
-              return new LinkedBlockingDeque<SumAndCount>(numWindows);
+              return new LinkedBlockingDeque<>(numWindows);
             }
           });
       final SumAndCount sumAndCount = new SumAndCount(

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/metrics2/lib/MetricsTestHelper.java

@@ -0,0 +1,49 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.metrics2.lib;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A helper class that can provide test cases access to package-private
+ * methods.
+ */
+public final class MetricsTestHelper {
+  public static final Logger LOG =
+      LoggerFactory.getLogger(MetricsTestHelper.class);
+
+  private MetricsTestHelper() {
+    //not called
+  }
+
+  /**
+   * Replace the rolling averages windows for a
+   * {@link MutableRollingAverages} metric.
+   *
+   */
+  public static void replaceRollingAveragesScheduler(
+      MutableRollingAverages mutableRollingAverages,
+      int numWindows, long interval, TimeUnit timeUnit) {
+    mutableRollingAverages.replaceScheduledTask(
+        numWindows, interval, timeUnit);
+  }
+}

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/metrics2/lib/TestMutableRollingAverages.java

@@ -17,23 +17,30 @@
  */
 package org.apache.hadoop.metrics2.lib;
 
+import com.google.common.base.Supplier;
+import org.apache.hadoop.metrics2.MetricsRecordBuilder;
+import org.apache.hadoop.metrics2.annotation.Metric;
+import org.apache.hadoop.test.GenericTestUtils;
+
+import org.apache.hadoop.util.Time;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
 import static org.apache.hadoop.metrics2.lib.Interns.info;
-import static org.apache.hadoop.test.MetricsAsserts.mockMetricsRecordBuilder;
+import static org.apache.hadoop.test.MetricsAsserts.*;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.verify;
 import static org.mockito.Matchers.anyDouble;
 import static org.mockito.Matchers.eq;
-
+import static org.mockito.Mockito.*;
-import org.apache.hadoop.metrics2.MetricsRecordBuilder;
-import org.apache.hadoop.util.Time;
-import org.junit.Test;
 
 /**
  * This class tests various cases of the algorithms implemented in
- * {@link RollingAverages}.
+ * {@link MutableRollingAverages}.
  */
-public class TestRollingAverages {
+public class TestMutableRollingAverages {
+
   /**
    * Tests if the results are correct if no samples are inserted, dry run of
    * empty roll over.
@@ -42,8 +49,9 @@ public class TestRollingAverages {
   public void testRollingAveragesEmptyRollover() throws Exception {
     final MetricsRecordBuilder rb = mockMetricsRecordBuilder();
     /* 5s interval and 2 windows */
-    try (RollingAverages rollingAverages =
+    try (MutableRollingAverages rollingAverages =
-             new RollingAverages(5000, 2)) {
+             new MutableRollingAverages("Time")) {
+      rollingAverages.replaceScheduledTask(2, 5, TimeUnit.SECONDS);
       /* Check it initially */
       rollingAverages.snapshot(rb, true);
       verify(rb, never()).addGauge(
@@ -78,9 +86,9 @@ public void testRollingAveragesRollover() throws Exception {
     final int windowSizeMs = 5000; // 5s roll over interval
     final int numWindows = 2;
     final int numOpsPerIteration = 1000;
-    try (RollingAverages rollingAverages = new RollingAverages(windowSizeMs,
+    try (MutableRollingAverages rollingAverages =
-        numWindows)) {
+             new MutableRollingAverages("Time")) {
-
+      rollingAverages.replaceScheduledTask(2, 5000, TimeUnit.MILLISECONDS);
       /* Push values for three intervals */
       final long start = Time.monotonicNow();
       for (int i = 1; i <= 3; i++) {
@@ -121,4 +129,64 @@ public void testRollingAveragesRollover() throws Exception {
       }
     }
   }
+
+  /**
+   * Test that MutableRollingAverages gives expected results after
+   * initialization.
+   * @throws Exception
+   */
+  @Test(timeout = 30000)
+  public void testMutableRollingAveragesMetric() throws Exception {
+    DummyTestMetric testMetric = new DummyTestMetric();
+    testMetric.create();
+
+    testMetric.add("metric1", 100);
+    testMetric.add("metric1", 900);
+    testMetric.add("metric2", 1000);
+    testMetric.add("metric2", 1000);
+
+    GenericTestUtils.waitFor(new Supplier<Boolean>() {
+      @Override
+      public Boolean get() {
+        testMetric.collectThreadLocalStates();
+        return testMetric.getStats().size() > 0;
+      }
+    }, 500, 5000);
+
+    MetricsRecordBuilder rb = getMetrics(DummyTestMetric.METRIC_NAME);
+
+    double metric1Avg = getDoubleGauge("[Metric1]RollingAvgTesting", rb);
+    double metric2Avg = getDoubleGauge("[Metric2]RollingAvgTesting", rb);
+    Assert.assertTrue("The rolling average of metric1 is not as expected",
+        metric1Avg == 500.0);
+    Assert.assertTrue("The rolling average of metric2 is not as expected",
+        metric2Avg == 1000.0);
+
+  }
+
+  class DummyTestMetric {
+    @Metric (valueName = "testing")
+    private MutableRollingAverages rollingAverages;
+
+    static final String METRIC_NAME = "RollingAveragesTestMetric";
+
+    protected void create() {
+      DefaultMetricsSystem.instance().register(METRIC_NAME,
+          "mutable rolling averages test", this);
+      rollingAverages.replaceScheduledTask(10, 1000, TimeUnit.MILLISECONDS);
+    }
+
+    void add(String name, long latency) {
+      rollingAverages.add(name, latency);
+    }
+
+    void collectThreadLocalStates() {
+      rollingAverages.collectThreadLocalStates();
+    }
+
+    Map<String, Double> getStats() {
+      return rollingAverages.getStats(0);
+    }
+
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -465,18 +465,6 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
       HdfsClientConfigKeys.DeprecatedKeys.DFS_METRICS_SESSION_ID_KEY;
   public static final String  DFS_METRICS_PERCENTILES_INTERVALS_KEY = "dfs.metrics.percentiles.intervals";
 
-  // The following setting is not meant to be changed by administrators.
-  public static final String DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_KEY =
-      "dfs.metrics.rolling.averages.window.length";
-  public static final String DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_DEFAULT =
-      "5m";
-
-  // The following setting is not meant to be changed by administrators.
-  public static final String DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_KEY =
-      "dfs.metrics.rolling.average.num.windows";
-  public static final int DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_DEFAULT =
-      36;
-
   public static final String  DFS_DATANODE_PEER_STATS_ENABLED_KEY =
       "dfs.datanode.peer.stats.enabled";
   public static final boolean DFS_DATANODE_PEER_STATS_ENABLED_DEFAULT = false;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -1415,7 +1415,7 @@ void startDataNode(List<StorageLocation> dataDirectories,
 
     metrics = DataNodeMetrics.create(getConf(), getDisplayName());
     peerMetrics = dnConf.peerStatsEnabled ?
-        DataNodePeerMetrics.create(getConf(), getDisplayName()) : null;
+        DataNodePeerMetrics.create(getDisplayName()) : null;
     metrics.getJvmMetrics().setPauseMonitor(pauseMonitor);
 
     ecWorker = new ErasureCodingWorker(getConf(), this);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/metrics/DataNodePeerMetrics.java

@@ -22,16 +22,13 @@
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.metrics2.MetricsJsonBuilder;
-import org.apache.hadoop.metrics2.lib.RollingAverages;
+import org.apache.hadoop.metrics2.lib.MutableRollingAverages;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Map;
 import java.util.concurrent.ThreadLocalRandom;
-import java.util.concurrent.TimeUnit;
 
 /**
  * This class maintains DataNode peer metrics (e.g. numOps, AvgTime, etc.) for
@@ -44,7 +41,7 @@ public class DataNodePeerMetrics {
   public static final Logger LOG = LoggerFactory.getLogger(
       DataNodePeerMetrics.class);
 
-  private final RollingAverages sendPacketDownstreamRollingAvgerages;
+  private final MutableRollingAverages sendPacketDownstreamRollingAverages;
 
   private final String name;
 
@@ -64,15 +61,11 @@ public class DataNodePeerMetrics {
   @VisibleForTesting
   static final long MIN_OUTLIER_DETECTION_SAMPLES = 1000;
 
-  public DataNodePeerMetrics(
+  public DataNodePeerMetrics(final String name) {
-      final String name,
-      final long windowSizeMs,
-      final int numWindows) {
     this.name = name;
     this.slowNodeDetector = new OutlierDetector(MIN_OUTLIER_DETECTION_NODES,
         LOW_THRESHOLD_MS);
-    sendPacketDownstreamRollingAvgerages = new RollingAverages(
+    sendPacketDownstreamRollingAverages = new MutableRollingAverages("Time");
-        windowSizeMs, numWindows);
   }
 
   public String name() {
@@ -82,23 +75,12 @@ public String name() {
   /**
    * Creates an instance of DataNodePeerMetrics, used for registration.
    */
-  public static DataNodePeerMetrics create(Configuration conf, String dnName) {
+  public static DataNodePeerMetrics create(String dnName) {
     final String name = "DataNodePeerActivity-" + (dnName.isEmpty()
         ? "UndefinedDataNodeName" + ThreadLocalRandom.current().nextInt()
         : dnName.replace(':', '-'));
 
-    final long windowSizeMs = conf.getTimeDuration(
+    return new DataNodePeerMetrics(name);
-            DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_KEY,
-            DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_DEFAULT,
-            TimeUnit.MILLISECONDS);
-    final int numWindows = conf.getInt(
-        DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_KEY,
-        DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_DEFAULT);
-
-    return new DataNodePeerMetrics(
-        name,
-        windowSizeMs,
-        numWindows);
   }
 
   /**
@@ -112,7 +94,7 @@ public static DataNodePeerMetrics create(Configuration conf, String dnName) {
   public void addSendPacketDownstream(
       final String peerAddr,
       final long elapsedMs) {
-    sendPacketDownstreamRollingAvgerages.add(peerAddr, elapsedMs);
+    sendPacketDownstreamRollingAverages.add(peerAddr, elapsedMs);
   }
 
   /**
@@ -120,7 +102,7 @@ public void addSendPacketDownstream(
    */
   public String dumpSendPacketDownstreamAvgInfoAsJson() {
     final MetricsJsonBuilder builder = new MetricsJsonBuilder(null);
-    sendPacketDownstreamRollingAvgerages.snapshot(builder, true);
+    sendPacketDownstreamRollingAverages.snapshot(builder, true);
     return builder.toString();
   }
 
@@ -128,7 +110,7 @@ public String dumpSendPacketDownstreamAvgInfoAsJson() {
    * Collects states maintained in {@link ThreadLocal}, if any.
    */
   public void collectThreadLocalStates() {
-    sendPacketDownstreamRollingAvgerages.collectThreadLocalStates();
+    sendPacketDownstreamRollingAverages.collectThreadLocalStates();
   }
 
   /**
@@ -139,10 +121,14 @@ public Map<String, Double> getOutliers() {
     // This maps the metric name to the aggregate latency.
     // The metric name is the datanode ID.
     final Map<String, Double> stats =
-        sendPacketDownstreamRollingAvgerages.getStats(
+        sendPacketDownstreamRollingAverages.getStats(
             MIN_OUTLIER_DETECTION_SAMPLES);
     LOG.trace("DataNodePeerMetrics: Got stats: {}", stats);
 
     return slowNodeDetector.getOutliers(stats);
   }
+
+  public MutableRollingAverages getSendPacketDownstreamRollingAverages() {
+    return sendPacketDownstreamRollingAverages;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodePeerMetrics.java

@@ -23,6 +23,7 @@
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.server.datanode.metrics.DataNodePeerMetrics;
+import org.apache.hadoop.metrics2.lib.MetricsTestHelper;
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.conf.Configuration;
 import org.junit.Test;
@@ -42,16 +43,13 @@ public void testGetSendPacketDownstreamAvgInfo() throws Exception {
     final int numOpsPerIteration = 1000;
 
     final Configuration conf = new HdfsConfiguration();
-    conf.setTimeDuration(
-        DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_KEY,
-        windowSize, TimeUnit.SECONDS);
-    conf.setInt(DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_KEY,
-        numWindows);
     conf.setBoolean(DFSConfigKeys.DFS_DATANODE_PEER_STATS_ENABLED_KEY, true);
 
     final DataNodePeerMetrics peerMetrics = DataNodePeerMetrics.create(
-        conf,
         "Sample-DataNode");
+    MetricsTestHelper.replaceRollingAveragesScheduler(
+        peerMetrics.getSendPacketDownstreamRollingAverages(),
+        numWindows, windowSize, TimeUnit.SECONDS);
     final long start = Time.monotonicNow();
     for (int i = 1; i <= iterations; i++) {
       final String peerAddr = genPeerAddress();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/metrics/TestDataNodeOutlierDetectionViaMetrics.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.hdfs.server.datanode.metrics;
 
 import com.google.common.base.Supplier;
+import org.apache.hadoop.metrics2.lib.MetricsTestHelper;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.log4j.Level;
 import org.junit.Before;
@@ -30,6 +31,7 @@
 
 import java.util.Map;
 import java.util.Random;
+import java.util.concurrent.TimeUnit;
 
 import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertThat;
@@ -73,8 +75,12 @@ public void testOutlierIsDetected() throws Exception {
     final String slowNodeName = "SlowNode";
 
     DataNodePeerMetrics peerMetrics = new DataNodePeerMetrics(
-        "PeerMetrics-For-Test", WINDOW_INTERVAL_SECONDS,
+        "PeerMetrics-For-Test");
-        ROLLING_AVERAGE_WINDOWS);
+
+    MetricsTestHelper.replaceRollingAveragesScheduler(
+        peerMetrics.getSendPacketDownstreamRollingAverages(),
+        ROLLING_AVERAGE_WINDOWS,
+        WINDOW_INTERVAL_SECONDS, TimeUnit.SECONDS);
 
     injectFastNodesSamples(peerMetrics);
     injectSlowNodeSamples(peerMetrics, slowNodeName);
@@ -101,8 +107,12 @@ public Boolean get() {
   @Test
   public void testWithNoOutliers() throws Exception {
     DataNodePeerMetrics peerMetrics = new DataNodePeerMetrics(
-        "PeerMetrics-For-Test", WINDOW_INTERVAL_SECONDS,
+        "PeerMetrics-For-Test");
-        ROLLING_AVERAGE_WINDOWS);
+
+    MetricsTestHelper.replaceRollingAveragesScheduler(
+        peerMetrics.getSendPacketDownstreamRollingAverages(),
+        ROLLING_AVERAGE_WINDOWS,
+        WINDOW_INTERVAL_SECONDS, TimeUnit.SECONDS);
 
     injectFastNodesSamples(peerMetrics);
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestHdfsConfigFields.java

@@ -66,10 +66,6 @@ public void initializeMemberVariables() {
     // Purposely hidden, based on comments in DFSConfigKeys
     configurationPropsToSkipCompare
         .add(DFSConfigKeys.DFS_DATANODE_XCEIVER_STOP_TIMEOUT_MILLIS_KEY);
-    configurationPropsToSkipCompare
-        .add(DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGES_WINDOW_LENGTH_KEY);
-    configurationPropsToSkipCompare
-        .add(DFSConfigKeys.DFS_METRICS_ROLLING_AVERAGE_NUM_WINDOWS_KEY);
 
     // Fully deprecated properties?
     configurationPropsToSkipCompare