anjy7 commented on code in PR #22669: URL: https://github.com/apache/kafka/pull/22669#discussion_r3572656526
########## jmh-benchmarks/src/main/java/org/apache/kafka/jmh/raft/LeaderBenchmarks.java: ########## @@ -0,0 +1,96 @@ +/* + * 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.raft; + +import org.apache.kafka.common.protocol.ApiKeys; +import org.apache.kafka.raft.RaftClientBenchmarkContext; +import org.apache.kafka.raft.RaftClientTestContext; + +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.Warmup; + +import java.util.Optional; +import java.util.concurrent.TimeUnit; + +/** + * Benchmarks for the leader request-handling path. The outer class is intentionally not a JMH + * {@code @State}: each benchmark declares the starting state it needs as a nested {@code @State} + * parameter, so future leader scenarios (e.g. a lagging-follower fetch or a commit) can have their own + * setup without forcing a single shared {@code @Setup} on the whole class. + */ +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(TimeUnit.NANOSECONDS) +@Warmup(iterations = RaftClientBenchmarkContext.AVERAGE_TIME_WARMUP_ITERATIONS) +@Measurement(iterations = RaftClientBenchmarkContext.AVERAGE_TIME_MEASUREMENT_ITERATIONS) +@Fork(RaftClientBenchmarkContext.AVERAGE_TIME_FORKS) +public class LeaderBenchmarks { + + /** + * Starting state: the local node is leader with the high watermark at the log end. + */ + @State(Scope.Thread) + public static class LeaderWithHwmAtLogEnd { + static final int VOTER_COUNT = 3; + + RaftClientBenchmarkContext benchmark; + RaftClientTestContext context; + + int epoch; + long endOffset; + + @Setup(Level.Trial) + public void setup() throws Exception { + benchmark = RaftClientBenchmarkContext.leader(VOTER_COUNT); + context = benchmark.testContext(); + context.advanceLocalLeaderHighWatermarkToLogEndOffset(); + epoch = context.currentEpoch(); + endOffset = benchmark.logEndOffset(); + benchmark.zeroCountersOnSetup(); + } + } + + /** + * Leader handles a FETCH from a fully caught-up follower (fetch offset == log end offset) that asks + * not to wait ({@code maxWaitMs = 0}), so the leader replies immediately rather than deferring. + * + * <p>Note: a real caught-up follower long-polls with {@code maxWaitMs > 0}, and such a fetch is + * <em>deferred</em> (held until new data arrives or the wait times out) — it would not produce an + * immediate response. This benchmark deliberately uses {@code maxWaitMs = 0} to measure the + * immediate-reply path. + */ + @Benchmark + public void handleNoWaitFetchFromCaughtUpFollower( + LeaderWithHwmAtLogEnd state, + KRaftBenchmarkingCounters counters + ) throws Exception { Review Comment: not really, I'll make it more specific. -- 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]
