kamalcph commented on code in PR #22810: URL: https://github.com/apache/kafka/pull/22810#discussion_r3568437821
########## jmh-benchmarks/src/main/java/org/apache/kafka/jmh/producer/ProducerMetadataAddBenchmark.java: ########## @@ -0,0 +1,122 @@ +/* + * 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.jmh.producer; + +import org.apache.kafka.clients.producer.internals.ProducerMetadata; +import org.apache.kafka.common.internals.ClusterResourceListeners; +import org.apache.kafka.common.utils.Time; +import org.apache.kafka.common.utils.internals.LogContext; + +import org.openjdk.jmh.annotations.Benchmark; +import org.openjdk.jmh.annotations.BenchmarkMode; +import org.openjdk.jmh.annotations.Fork; +import org.openjdk.jmh.annotations.Level; +import org.openjdk.jmh.annotations.Measurement; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.Setup; +import org.openjdk.jmh.annotations.State; +import org.openjdk.jmh.annotations.Threads; +import org.openjdk.jmh.annotations.Warmup; + +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import java.util.concurrent.ThreadLocalRandom; +import java.util.concurrent.TimeUnit; + +/** + * Compares {@link ProducerMetadata#add} against a baseline that mirrors the prior, fully + * {@code synchronized} implementation (map update + newTopics bookkeeping as a single + * {@code synchronized} block). Every {@code send()} call refreshes the expiry of the topic + * it's producing to via {@code add()}, so with many application threads sharing one producer, + * this refresh is on the hot path and contends across threads for a topic that's virtually + * always already tracked. This benchmark simulates that: many threads concurrently refreshing + * a shared pool of already-registered topics. + */ +@State(Scope.Benchmark) +@Fork(value = 1) +@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS) +@Measurement(iterations = 10, time = 1, timeUnit = TimeUnit.SECONDS) +@BenchmarkMode(Mode.Throughput) +@OutputTimeUnit(TimeUnit.MILLISECONDS) +@Threads(8) +public class ProducerMetadataAddBenchmark { + + private static final int TOPIC_COUNT = 200; + private static final long METADATA_IDLE_MS = TimeUnit.MINUTES.toMillis(5); + + private String[] topics; + private ProducerMetadata lockFreeHotPathMetadata; + private FullySynchronizedProducerMetadata fullySynchronizedMetadata; + + @Setup(Level.Trial) + public void setup() { + topics = new String[TOPIC_COUNT]; + for (int i = 0; i < TOPIC_COUNT; i++) { + topics[i] = "topic-" + i; + } + + lockFreeHotPathMetadata = new ProducerMetadata(100L, 1000L, TimeUnit.MINUTES.toMillis(5), METADATA_IDLE_MS, + new LogContext(), new ClusterResourceListeners(), Time.SYSTEM); + fullySynchronizedMetadata = new FullySynchronizedProducerMetadata(METADATA_IDLE_MS); + + long nowMs = Time.SYSTEM.milliseconds(); + for (String topic : topics) { + lockFreeHotPathMetadata.add(topic, nowMs); + fullySynchronizedMetadata.add(topic, nowMs); + } + } + + @Benchmark + public void addExistingTopicFullySynchronized() { + String topic = topics[ThreadLocalRandom.current().nextInt(TOPIC_COUNT)]; + fullySynchronizedMetadata.add(topic, Time.SYSTEM.milliseconds()); + } + + @Benchmark + public void addExistingTopicLockFreeHotPath() { + String topic = topics[ThreadLocalRandom.current().nextInt(TOPIC_COUNT)]; + lockFreeHotPathMetadata.add(topic, Time.SYSTEM.milliseconds()); + } + + /** + * Baseline mirroring the prior {@code ProducerMetadata#add}: a plain {@code HashMap} + * guarded end-to-end by a single {@code synchronized} method, so every call - including a + * refresh of an already-tracked topic - serializes on the instance lock. + */ + private static class FullySynchronizedProducerMetadata { Review Comment: Do we need this class? Shall we show the improvement before and after this patch? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
