diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCMetrics.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCMetrics.java
index 9ab4e5addb..cce4b86ce1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCMetrics.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCMetrics.java
@@ -85,15 +85,6 @@ public static FederationRPCMetrics create(Configuration conf,
         new FederationRPCMetrics(conf, rpcServer));
   }
 
-  /**
-   * Convert nanoseconds to milliseconds.
-   * @param ns Time in nanoseconds.
-   * @return Time in milliseconds.
-   */
-  private static double toMs(double ns) {
-    return ns / 1000000;
-  }
-
   /**
    * Reset the metrics system.
    */
@@ -230,7 +221,7 @@ public void addProxyTime(long time) {
 
   @Override
   public double getProxyAvg() {
-    return toMs(proxy.lastStat().mean());
+    return proxy.lastStat().mean();
   }
 
   @Override
@@ -250,7 +241,7 @@ public void addProcessingTime(long time) {
 
   @Override
   public double getProcessingAvg() {
-    return toMs(processing.lastStat().mean());
+    return processing.lastStat().mean();
   }
 
   @Override
diff --git a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCPerformanceMonitor.java b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCPerformanceMonitor.java
index 2c2741e559..15725d14ce 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCPerformanceMonitor.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/FederationRPCPerformanceMonitor.java
@@ -35,6 +35,8 @@
 
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 
+import static org.apache.hadoop.util.Time.monotonicNow;
+
 /**
  * Customizable RPC performance monitor. Receives events from the RPC server
  * and aggregates them via JMX.
@@ -120,12 +122,12 @@ public void resetPerfCounters() {
 
   @Override
   public void startOp() {
-    START_TIME.set(this.getNow());
+    START_TIME.set(monotonicNow());
   }
 
   @Override
   public long proxyOp() {
-    PROXY_TIME.set(this.getNow());
+    PROXY_TIME.set(monotonicNow());
     long processingTime = getProcessingTime();
     if (processingTime >= 0) {
       metrics.addProcessingTime(processingTime);
@@ -188,13 +190,6 @@ public void routerFailureLocked() {
     metrics.incrRouterFailureLocked();
   }
 
-  /**
-   * Get current time.
-   * @return Current time in nanoseconds.
-   */
-  private long getNow() {
-    return System.nanoTime();
-  }
 
   /**
    * Get time between we receiving the operation and sending it to the Namenode.
@@ -214,7 +209,7 @@ private long getProcessingTime() {
    */
   private long getProxyTime() {
     if (PROXY_TIME.get() != null && PROXY_TIME.get() > 0) {
-      return getNow() - PROXY_TIME.get();
+      return monotonicNow() - PROXY_TIME.get();
     }
     return -1;
   }