cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From jji...@apache.org
Subject [04/10] cassandra git commit: Fix negative mean latency metric
Date Sun, 12 Feb 2017 07:32:00 GMT
Fix negative mean latency metric

Patch by Per Otterstrom; Reviewed by Chris Lohfink for CASSANDRA-12876


Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/7e05f393
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/7e05f393
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/7e05f393

Branch: refs/heads/trunk
Commit: 7e05f393f39c90ec0447b1cc893ff46901ae3071
Parents: c884b70
Author: Per Otterstrom <per.otterstrom@ericsson.com>
Authored: Wed Jan 18 14:56:01 2017 +0100
Committer: Jeff Jirsa <jeff@jeffjirsa.net>
Committed: Sat Feb 11 23:28:35 2017 -0800

----------------------------------------------------------------------
 CHANGES.txt                                     |  1 +
 .../DecayingEstimatedHistogramReservoir.java    |  3 +-
 ...DecayingEstimatedHistogramReservoirTest.java | 31 ++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/cassandra/blob/7e05f393/CHANGES.txt
----------------------------------------------------------------------
diff --git a/CHANGES.txt b/CHANGES.txt
index fc79796..214fe97 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 2.2.9
+ * Fix negative mean latency metric (CASSANDRA-12876)
  * Use only one file pointer when creating commitlog segments (CASSANDRA-12539)
  * Fix speculative retry bugs (CASSANDRA-13009)
  * Fix handling of nulls and unsets in IN conditions (CASSANDRA-12981) 

http://git-wip-us.apache.org/repos/asf/cassandra/blob/7e05f393/src/java/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoir.java
----------------------------------------------------------------------
diff --git a/src/java/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoir.java
b/src/java/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoir.java
index 2458164..2f8bdf8 100644
--- a/src/java/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoir.java
+++ b/src/java/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoir.java
@@ -352,11 +352,12 @@ public class DecayingEstimatedHistogramReservoir implements Reservoir
         public EstimatedHistogramReservoirSnapshot(DecayingEstimatedHistogramReservoir reservoir)
         {
             final int length = reservoir.decayingBuckets.length();
+            final double rescaleFactor = forwardDecayWeight(clock.getTime());
 
             this.decayingBuckets = new long[length];
 
             for (int i = 0; i < length; i++)
-                this.decayingBuckets[i] = reservoir.decayingBuckets.get(i);
+                this.decayingBuckets[i] = Math.round(reservoir.decayingBuckets.get(i) / rescaleFactor);
         }
 
         /**

http://git-wip-us.apache.org/repos/asf/cassandra/blob/7e05f393/test/unit/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoirTest.java
----------------------------------------------------------------------
diff --git a/test/unit/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoirTest.java
b/test/unit/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoirTest.java
index f2d817f..ef1fed3 100644
--- a/test/unit/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoirTest.java
+++ b/test/unit/org/apache/cassandra/metrics/DecayingEstimatedHistogramReservoirTest.java
@@ -354,6 +354,32 @@ public class DecayingEstimatedHistogramReservoirTest
         }
     }
 
+    @Test
+    public void testDecayingMean()
+    {
+        {
+            TestClock clock = new TestClock();
+
+            DecayingEstimatedHistogramReservoir histogram = new DecayingEstimatedHistogramReservoir(DecayingEstimatedHistogramReservoir.DEFAULT_ZERO_CONSIDERATION,
DecayingEstimatedHistogramReservoir.DEFAULT_BUCKET_COUNT, clock);
+
+            clock.addMillis(DecayingEstimatedHistogramReservoir.LANDMARK_RESET_INTERVAL_IN_MS
- 1_000L);
+
+            while (clock.getTime() < DecayingEstimatedHistogramReservoir.LANDMARK_RESET_INTERVAL_IN_MS
+ 1_000L)
+            {
+                clock.addMillis(900);
+                for (int i = 0; i < 1_000_000; i++)
+                {
+                    histogram.update(1000);
+                    histogram.update(2000);
+                    histogram.update(3000);
+                    histogram.update(4000);
+                    histogram.update(5000);
+                }
+                assertEquals(3000D, histogram.getSnapshot().getMean(), 500D);
+            }
+        }
+    }
+
     private void assertEstimatedQuantile(long expectedValue, double actualValue)
     {
         assertTrue("Expected at least [" + expectedValue + "] but actual is [" + actualValue
+ "]", actualValue >= expectedValue);
@@ -363,6 +389,11 @@ public class DecayingEstimatedHistogramReservoirTest
     public class TestClock extends Clock {
         private long tick = 0;
 
+        public void addMillis(long millis)
+        {
+            tick += millis * 1_000_000L;
+        }
+
         public void addSeconds(long seconds)
         {
             tick += seconds * 1_000_000_000L;


Mime
View raw message