emitskevich-blp commented on code in PR #15889: URL: https://github.com/apache/kafka/pull/15889#discussion_r1610653813
########## clients/src/test/java/org/apache/kafka/common/metrics/stats/SampledStatTest.java: ########## @@ -0,0 +1,110 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.kafka.common.metrics.stats; + +import org.apache.kafka.common.metrics.MetricConfig; +import org.apache.kafka.common.utils.MockTime; +import org.apache.kafka.common.utils.Time; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.DisplayName; +import org.junit.jupiter.api.Test; + +import java.util.List; + +import static java.util.concurrent.TimeUnit.SECONDS; +import static org.junit.jupiter.api.Assertions.assertEquals; + +class SampledStatTest { + + private SampledStat stat; + private Time time; + + @BeforeEach + public void setup() { + stat = new SampleCount(0); + time = new MockTime(); + } + + @Test + @DisplayName("Sample should be purged if doesn't overlap the window") + public void testSampleIsPurgedIfDoesntOverlap() { + MetricConfig config = new MetricConfig().timeWindow(1, SECONDS).samples(2); + + // Monitored window: 2s. Complete a sample and wait 2.5s after. + completeSample(config); + time.sleep(2500); + + double numSamples = stat.measure(config, time.milliseconds()); + assertEquals(0, numSamples); + } + + @Test + @DisplayName("Sample should be kept if overlaps the window") + public void testSampleIsKeptIfOverlaps() { + MetricConfig config = new MetricConfig().timeWindow(1, SECONDS).samples(2); + + // Monitored window: 2s. Complete a sample and wait 1.5s after. + completeSample(config); + time.sleep(1500); + + double numSamples = stat.measure(config, time.milliseconds()); + assertEquals(1, numSamples); + } + + @Test + @DisplayName("Sample should be kept if overlaps the window and is n+1") + public void testSampleIsKeptIfOverlapsAndExtra() { + MetricConfig config = new MetricConfig().timeWindow(1, SECONDS).samples(2); + + // Monitored window: 2s. Create 2 samples with gaps in between and + // take a measurement at 2.2s from the start. + completeSample(config); + time.sleep(100); + completeSample(config); + time.sleep(100); + stat.record(config, 1, time.milliseconds()); + + double numSamples = stat.measure(config, time.milliseconds()); + assertEquals(3, numSamples); + } + + // Creates a sample with events at the start and at the end. Positions clock at the end. + private void completeSample(MetricConfig config) { + stat.record(config, 1, time.milliseconds()); + time.sleep(config.timeWindowMs() - 1); + stat.record(config, 1, time.milliseconds()); + time.sleep(1); + } + + // measure() of this impl returns the number of samples + static class SampleCount extends SampledStat { + + SampleCount(double initialValue) { Review Comment: Applied ########## clients/src/main/java/org/apache/kafka/common/metrics/stats/SampledStat.java: ########## @@ -40,7 +40,7 @@ public abstract class SampledStat implements MeasurableStat { public SampledStat(double initialValue) { this.initialValue = initialValue; - this.samples = new ArrayList<>(2); + this.samples = new ArrayList<>(3); Review Comment: Addressed -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
