From fe5c23b670c773145b87fecfaf9191536e9f1c51 Mon Sep 17 00:00:00 2001
From: Karthik Kambatla <kasha@apache.org>
Date: Fri, 20 Mar 2015 17:03:03 -0700
Subject: [PATCH] HADOOP-11447. Add a more meaningful toString method to
 SampleStat and MutableStat. (kasha)

---
 hadoop-common-project/hadoop-common/CHANGES.txt     |  3 +++
 .../org/apache/hadoop/metrics2/lib/MutableStat.java |  4 ++++
 .../org/apache/hadoop/metrics2/util/SampleStat.java | 13 +++++++++++++
 3 files changed, 20 insertions(+)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 823a36bad7..4cd21542a7 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -455,6 +455,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-11709. Time.NANOSECONDS_PER_MILLISECOND - use class-level final
     constant instead of method variable (Ajith S via ozawa)
 
+    HADOOP-11447. Add a more meaningful toString method to SampleStat and 
+    MutableStat. (kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableStat.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableStat.java
index ba377570ef..d794e8eeed 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableStat.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/lib/MutableStat.java
@@ -151,4 +151,8 @@ public void resetMinMax() {
     minMax.reset();
   }
 
+  @Override
+  public String toString() {
+    return lastStat().toString();
+  }
 }
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/util/SampleStat.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/util/SampleStat.java
index 589062a691..cd9aaa49e1 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/util/SampleStat.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/util/SampleStat.java
@@ -137,6 +137,19 @@ public double max() {
     return minmax.max();
   }
 
+  @Override
+  public String toString() {
+    try {
+      return "Samples = " + numSamples() +
+          "  Min = " + min() +
+          "  Mean = " + mean() +
+          "  Std Dev = " + stddev() +
+          "  Max = " + max();
+    } catch (Throwable t) {
+      return super.toString();
+    }
+  }
+
   /**
    * Helper to keep running min/max
    */