TestDataNodeOutlierDetectionViaMetrics UT fails

Failed tests: 
  TestDataNodeOutlierDetectionViaMetrics.testOutlierIsDetected:86 
Expected: is <1>
     but: was <0>

Tests run: 300, Failures: 1, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] Apache Hadoop Common ............................... SUCCESS [ 11.586 s]
[INFO] Apache Hadoop HDFS ................................. FAILURE [24:16 min]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

Error Message

Expected: is <1>
     but: was <0>
Stacktrace

java.lang.AssertionError: 
Expected: is <1>
     but: was <0>
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
	at org.junit.Assert.assertThat(Assert.java:865)
	at org.junit.Assert.assertThat(Assert.java:832)
	at org.apache.hadoop.hdfs.server.datanode.metrics.TestDataNodeOutlierDetectionViaMetrics.testOutlierIsDetected(TestDataNodeOutlierDetectionViaMetrics.java:86)