Calculate first response metrics from sent time #491

Latency collection calculates firstResponse latency using sent time as reference. First response latency reflects the time between sending and receiving (processing) the first chunk of data for the command. Previously firstResponse latency was calculated between first response time and command completion.
redis · Mar 20, 2017 · 7063839 · 7063839
1 parent b616b5a
commit 7063839
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diff --git a/src/main/java/com/lambdaworks/redis/protocol/CommandHandler.java b/src/main/java/com/lambdaworks/redis/protocol/CommandHandler.java
@@ -253,7 +253,7 @@ private void recordLatency(WithLatency withLatency, ProtocolKeyword commandType)
         if (withLatency != null && clientResources.commandLatencyCollector().isEnabled() && channel != null
                 && remote() != null) {
 
-            long firstResponseLatency = nanoTime() - withLatency.getFirstResponse();
+            long firstResponseLatency = withLatency.getSent() - withLatency.getFirstResponse();
             long completionLatency = nanoTime() - withLatency.getSent();
 
             clientResources.commandLatencyCollector().recordCommandLatency(local(), remote(), commandType, firstResponseLatency,

diff --git a/src/test/java/com/lambdaworks/redis/metrics/DefaultCommandLatencyCollectorTest.java b/src/test/java/com/lambdaworks/redis/metrics/DefaultCommandLatencyCollectorTest.java
@@ -71,6 +71,9 @@ public void verifyMetrics() {
         assertThat(metrics.getFirstResponse().getMax()).isBetween(290000L, 310000L);
         assertThat(metrics.getCompletion().getPercentiles()).containsKey(50.0d);
 
+        assertThat(metrics.getFirstResponse().getPercentiles().get(50d)).isLessThanOrEqualTo(
+                metrics.getCompletion().getPercentiles().get(50d));
+
         assertThat(metrics.getTimeUnit()).isEqualTo(MICROSECONDS);
 
         assertThat(sut.retrieveMetrics()).isEmpty();