Merge pull request #262 from dmuino/distSummaryMin

Add min gauge to distribution summary
Netflix · Jul 16, 2014 · 1df3974 · 1df3974
2 parents bd949ad + a323824
commit 1df3974
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Showing 2 changed files with 19 additions and 3 deletions.
diff --git a/servo-core/src/main/java/com/netflix/servo/monitor/BasicDistributionSummary.java b/servo-core/src/main/java/com/netflix/servo/monitor/BasicDistributionSummary.java
@@ -33,10 +33,12 @@ public class BasicDistributionSummary
     private static final Tag STAT_TOTAL = Tags.newTag(STATISTIC, "totalAmount");
     private static final Tag STAT_COUNT = Tags.newTag(STATISTIC, "count");
     private static final Tag STAT_MAX = Tags.newTag(STATISTIC, "max");
+    private static final Tag STAT_MIN = Tags.newTag(STATISTIC, "min");
 
     private final StepCounter totalAmount;
     private final StepCounter count;
     private final MaxGauge max;
+    private final MinGauge min;
 
     private final List<Monitor<?>> monitors;
 
@@ -49,8 +51,9 @@ public BasicDistributionSummary(MonitorConfig config) {
         totalAmount = new StepCounter(config.withAdditionalTag(STAT_TOTAL));
         count = new StepCounter(config.withAdditionalTag(STAT_COUNT));
         max = new MaxGauge(config.withAdditionalTag(STAT_MAX));
+        min = new MinGauge(config.withAdditionalTag(STAT_MIN));
 
-        monitors = ImmutableList.<Monitor<?>>of(totalAmount, count, max);
+        monitors = ImmutableList.<Monitor<?>>of(totalAmount, count, max, min);
     }
 
     /**
@@ -69,6 +72,7 @@ public void record(long amount) {
             totalAmount.increment(amount);
             count.increment();
             max.update(amount);
+            min.update(amount);
         }
     }
 
@@ -97,6 +101,13 @@ public Long getCount() {
         return count.getCurrentCount(0);
     }
 
+    /**
+     * Get the min value since the last polling interval.
+     */
+    public Long getMin() {
+        return min.getCurrentValue(0);
+    }
+
     /**
      * Get the max value since the last polling interval.
      */
@@ -113,6 +124,7 @@ public String toString() {
                 .add("config", config)
                 .add("totalAmount", totalAmount)
                 .add("count", count)
+                .add("min", min)
                 .add("max", max).toString();
     }
 
@@ -121,7 +133,7 @@ public String toString() {
      */
     @Override
     public int hashCode() {
-        return Objects.hashCode(config, totalAmount, count, max);
+        return Objects.hashCode(config, totalAmount, count, max, min);
     }
 
     /**
@@ -141,6 +153,7 @@ public boolean equals(Object obj) {
         return config.equals(m.getConfig())
                 && totalAmount.equals(m.totalAmount)
                 && count.equals(m.count)
-                && max.equals(m.max);
+                && max.equals(m.max)
+                && min.equals(m.min);
     }
 }
diff --git a/servo-core/src/test/java/com/netflix/servo/monitor/BasicDistributionSummaryTest.java b/servo-core/src/test/java/com/netflix/servo/monitor/BasicDistributionSummaryTest.java
@@ -32,17 +32,20 @@ public void testGetValue() throws Exception {
         assertEquals(m.getCount().longValue(), 0L);
         assertEquals(m.getTotalAmount().longValue(), 0L);
         assertEquals(m.getMax().longValue(), 0L);
+        assertEquals(m.getMin().longValue(), 0L);
 
         m.record(42);
         assertEquals(m.getValue().longValue(), 42L);
         assertEquals(m.getTotalAmount().longValue(), 42L);
         assertEquals(m.getCount().longValue(), 1L);
         assertEquals(m.getMax().longValue(), 42L);
+        assertEquals(m.getMin().longValue(), 42L);
 
         m.record(21);
         assertEquals(m.getValue().longValue(), 31L);
         assertEquals(m.getTotalAmount().longValue(), 63L);
         assertEquals(m.getCount().longValue(), 2L);
         assertEquals(m.getMax().longValue(), 42L);
+        assertEquals(m.getMin().longValue(), 21L);
     }
 }