HADOOP-14894. ReflectionUtils should use Time.monotonicNow to mesaure duration. Contributed by Bharat Viswanadham.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ReflectionUtils.java

@@ -212,7 +212,7 @@ public class ReflectionUtils {
     boolean dumpStack = false;
     if (log.isInfoEnabled()) {
       synchronized (ReflectionUtils.class) {
-        long now = Time.now();
+        long now = Time.monotonicNow();
         if (now - previousLogTime >= minInterval * 1000) {
           previousLogTime = now;
           dumpStack = true;
@@ -241,7 +241,7 @@ public class ReflectionUtils {
     boolean dumpStack = false;
     if (log.isInfoEnabled()) {
       synchronized (ReflectionUtils.class) {
-        long now = Time.now();
+        long now = Time.monotonicNow();
         if (now - previousLogTime >= minInterval * 1000) {
           previousLogTime = now;
           dumpStack = true;