HADOOP-8913. hadoop-metrics2.properties should give units in comment for sampling period. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1396904 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/hadoop-common-project/hadoop-common/src/main/conf/hadoop-metrics2.properties b/hadoop-common-project/hadoop-common/src/main/conf/hadoop-metrics2.properties
index da57735..9e51b1c 100644
--- a/hadoop-common-project/hadoop-common/src/main/conf/hadoop-metrics2.properties
+++ b/hadoop-common-project/hadoop-common/src/main/conf/hadoop-metrics2.properties
@@ -2,7 +2,7 @@
 # See javadoc of package-info.java for org.apache.hadoop.metrics2 for details
 
 *.sink.file.class=org.apache.hadoop.metrics2.sink.FileSink
-# default sampling period
+# default sampling period, in seconds
 *.period=10
 
 # The namenode-metrics.out will contain metrics from all context
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/conf/hadoop-metrics2.properties b/hadoop-hdfs-project/hadoop-hdfs/src/main/conf/hadoop-metrics2.properties
index 586e066..c3ffe31 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/conf/hadoop-metrics2.properties
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/conf/hadoop-metrics2.properties
@@ -19,7 +19,7 @@
 # See javadoc of package-info.java for org.apache.hadoop.metrics2 for details
 
 *.sink.file.class=org.apache.hadoop.metrics2.sink.FileSink
-# default sampling period
+# default sampling period, in seconds
 *.period=10
 
 # The namenode-metrics.out will contain metrics from all context