Switch LatencyMetrics to use ThreadLocalTimer/ThreadLocalCounter

netudima · netudima · commit d7bd75303f25 · 2025-12-17T10:38:42.000Z
Patch by Dmitry Konstantinov; reviewed by Benedict Elliott Smith, Jyothsna Konisa for CASSANDRA-21080
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -1,4 +1,5 @@
 5.1
+ * Switch LatencyMetrics to use ThreadLocalTimer/ThreadLocalCounter (CASSANDRA-21080)
  * Accord: write rejections would be returned to users as server errors rather than INVALID and TxnReferenceOperation didn't handle all collections prperly (CASSANDRA-21061)
  * Use byte[] directly in QueryOptions instead of ByteBuffer and convert them to ArrayCell instead of BufferCell to reduce allocations (CASSANDRA-20166)
  * Log queries scanning too many SSTables per read (CASSANDRA-21048)
diff --git a/src/java/org/apache/cassandra/metrics/LatencyMetrics.java b/src/java/org/apache/cassandra/metrics/LatencyMetrics.java
@@ -167,7 +167,7 @@ public void release()
         Metrics.remove(factory.createMetricName(namePrefix + "TotalLatency"));
     }
 
-    public class LatencyMetricsTimer extends OverrideTimer implements org.apache.cassandra.metrics.Timer
+    public class LatencyMetricsTimer extends ThreadLocalTimer implements org.apache.cassandra.metrics.Timer
     {
         long releasedLatencyCount = 0;
 
@@ -246,7 +246,7 @@ public Snapshot getSnapshot()
         }
     }
 
-    class LatencyMetricsCounter extends Counter 
+    class LatencyMetricsCounter extends ThreadLocalCounter
     {
         @Override
         public long getCount()

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`5.1`
	`2`	`+ * Switch LatencyMetrics to use ThreadLocalTimer/ThreadLocalCounter (CASSANDRA-21080)`
`2`	`3`	`* Accord: write rejections would be returned to users as server errors rather than INVALID and TxnReferenceOperation didn't handle all collections prperly (CASSANDRA-21061)`
`3`	`4`	`* Use byte[] directly in QueryOptions instead of ByteBuffer and convert them to ArrayCell instead of BufferCell to reduce allocations (CASSANDRA-20166)`
`4`	`5`	`* Log queries scanning too many SSTables per read (CASSANDRA-21048)`
Original file line number	Diff line number	Diff line change
`@@ -167,7 +167,7 @@ public void release()`
`167`	`167`	`Metrics.remove(factory.createMetricName(namePrefix + "TotalLatency"));`
`168`	`168`	`}`
`169`	`169`
`170`		`- public class LatencyMetricsTimer extends OverrideTimer implements org.apache.cassandra.metrics.Timer`
	`170`	`+ public class LatencyMetricsTimer extends ThreadLocalTimer implements org.apache.cassandra.metrics.Timer`
`171`	`171`	`{`
`172`	`172`	`long releasedLatencyCount = 0;`
`173`	`173`
`@@ -246,7 +246,7 @@ public Snapshot getSnapshot()`
`246`	`246`	`}`
`247`	`247`	`}`
`248`	`248`
`249`		`- class LatencyMetricsCounter extends Counter`
	`249`	`+ class LatencyMetricsCounter extends ThreadLocalCounter`
`250`	`250`	`{`
`251`	`251`	`@Override`
`252`	`252`	`public long getCount()`