kevin-wu24 commented on code in PR #22669: URL: https://github.com/apache/kafka/pull/22669#discussion_r3507168086
########## raft/src/testFixtures/java/org/apache/kafka/raft/RaftClientBenchmarkContext.java: ########## @@ -0,0 +1,270 @@ +/* + * 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.raft; + +import org.apache.kafka.common.Uuid; +import org.apache.kafka.common.protocol.ApiKeys; +import org.apache.kafka.raft.RaftClientTestContext.RaftProtocol; +import org.apache.kafka.server.common.KRaftVersion; + +import java.util.Arrays; +import java.util.Comparator; +import java.util.List; +import java.util.Optional; +import java.util.concurrent.ThreadLocalRandom; +import java.util.function.IntSupplier; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public final class RaftClientBenchmarkContext { + // Standardized JMH iteration counts, shared by all raft benchmarks so every benchmark of a given + // mode is configured identically. + + // SingleShotTime measures a single operation per iteration, so it needs many iterations to build + // a stable distribution. + public static final int SINGLE_SHOT_WARMUP_ITERATIONS = 50; + public static final int SINGLE_SHOT_MEASUREMENT_ITERATIONS = 30; + public static final int SINGLE_SHOT_FORKS = 5; + + // AverageTime averages many operations within each timed iteration, so it needs fewer. + public static final int AVERAGE_TIME_WARMUP_ITERATIONS = 5; + public static final int AVERAGE_TIME_MEASUREMENT_ITERATIONS = 10; + public static final int AVERAGE_TIME_FORKS = 3; + + // Default to the newest version of each (the highest-ordinal enum constant). Enum natural order + // is ordinal order, so this picks the last-declared constant; relies on the constants being + // declared oldest-to-newest, which avoids updating these when a new version is added. + public static final KRaftVersion DEFAULT_KRAFT_VERSION = + Arrays.stream(KRaftVersion.values()).max(Comparator.naturalOrder()).orElseThrow(); + public static final RaftProtocol DEFAULT_RAFT_PROTOCOL = + Arrays.stream(RaftProtocol.values()).max(Comparator.naturalOrder()).orElseThrow(); + + private final RaftClientTestContext context; + private final MockLog log; + private final MockNetworkChannel channel; + private final List<ReplicaKey> voters; + + // Each tracks one cumulative mock counter as a drainable delta against a baseline. The baseline is + // reset by zeroCountersOnSetup() at the end of benchmark setup. + private final DrainableCounter logFlushes; + private final DrainableCounter logReads; + private final DrainableCounter logTruncations; + private final DrainableCounter rpcRequestsSent; + private final DrainableCounter quorumStateWrites; + private final DrainableCounter quorumStateReads; + + private RaftClientBenchmarkContext(RaftClientTestContext context, List<ReplicaKey> voters) { + this.context = context; + this.log = context.log; + this.channel = context.channel; + this.voters = List.copyOf(voters); + this.logFlushes = new DrainableCounter(log::flushCount); + this.logReads = new DrainableCounter(log::readCount); + this.logTruncations = new DrainableCounter(log::truncationCount); + this.rpcRequestsSent = new DrainableCounter(channel::requestsSent); + this.quorumStateWrites = new DrainableCounter(context::quorumStateWriteCount); + this.quorumStateReads = new DrainableCounter(context::quorumStateReadCount); + } + + /** + * Builds a local, unattached node in a {@code voterCount}-node cluster (the local node is not yet + * the leader). Use {@link RaftClientTestContext#unattachedToLeader()} on {@link #testContext()} as + * the measured operation to drive a full Unattached → Leader election. A single-voter cluster + * is rejected because such a node elects itself at initialization, before any measured poll. + */ + public static RaftClientBenchmarkContext unattached(int voterCount) throws Exception { + return unattached(voterCount, DEFAULT_KRAFT_VERSION, DEFAULT_RAFT_PROTOCOL); + } + + public static RaftClientBenchmarkContext unattached( + int voterCount, + KRaftVersion kraftVersion, + RaftProtocol raftProtocol + ) throws Exception { + if (voterCount < 2) { + throw new IllegalArgumentException("voterCount must be at least 2; a single voter self-elects at init"); + } + List<ReplicaKey> voterKeys = voterKeys(voterCount); + return new RaftClientBenchmarkContext(buildContext(voterKeys, kraftVersion, raftProtocol), voterKeys); + } + + public static RaftClientBenchmarkContext leader(int voterCount) throws Exception { + return leader(voterCount, DEFAULT_KRAFT_VERSION, DEFAULT_RAFT_PROTOCOL); + } + + public static RaftClientBenchmarkContext leader( + int voterCount, + KRaftVersion kraftVersion, + RaftProtocol raftProtocol + ) throws Exception { + List<ReplicaKey> voterKeys = voterKeys(voterCount); + RaftClientTestContext context = buildContext(voterKeys, kraftVersion, raftProtocol); + context.unattachedToLeader(); + + return new RaftClientBenchmarkContext(context, voterKeys); + } + + /** + * {@code voterCount} voter keys, each with a random directory id, with the local node first. + */ + private static List<ReplicaKey> voterKeys(int voterCount) { + int localId = randomReplicaId(); + return IntStream.range(0, voterCount) + .mapToObj(i -> ReplicaKey.of(localId + i, Uuid.randomUuid())) + .collect(Collectors.toList()); + } + + private static int randomReplicaId() { + return ThreadLocalRandom.current().nextInt(1025); + } + + /** + * Initializes a local, unattached node in a cluster of {@code voterKeys} (first entry is the local + * node). + */ + private static RaftClientTestContext buildContext( + List<ReplicaKey> voterKeys, + KRaftVersion kraftVersion, + RaftProtocol raftProtocol + ) throws Exception { + ReplicaKey local = voterKeys.get(0); + VoterSet voters = VoterSetTestUtil.voterSet(voterKeys.stream()); + + return new RaftClientTestContext.Builder(local.id(), local.directoryId().get()) + .withStartingVoters(voters, kraftVersion) + .withRaftProtocol(raftProtocol) + .withPollIntervalMs(0) + .withUnknownLeader(0) + .build(); + } + + public RaftClientTestContext testContext() { + return context; + } + + /** The local node's log end offset. Kept here because the {@code log} field is package-private. */ + public long logEndOffset() { + return log.endOffset().offset(); + } + + /** + * The voters other than the local node, in voter-set order. May be empty (single-voter cluster). + * Use these as the source of delivered requests, e.g. a FETCH from a follower on the leader. + */ + public List<ReplicaKey> remoteVoters() { + return voters.subList(1, voters.size()); + } + + /** + * Establishes the counter baseline so that work done before this point (building the context, + * driving an election in {@code leader()}, or anything else a benchmark does in its setup) is not + * attributed to the measured operation. Call this at the <b>end of benchmark setup</b>, just + * before the measured region begins. + */ + public void zeroCountersOnSetup() { + logFlushes.reset(); + logReads.reset(); + logTruncations.reset(); + rpcRequestsSent.reset(); + quorumStateWrites.reset(); + quorumStateReads.reset(); + channel.drainSendQueue(); + context.drainAllSentResponses(); + } + + public int getLogFlushesDelta() { + return logFlushes.delta(); + } + + public int getLogReadsDelta() { + return logReads.delta(); + } + + public int getLogTruncationsDelta() { + return logTruncations.delta(); + } + + /** + * Total number of requests (all API keys) the client has sent since the last call. Uses the + * channel's cumulative counter, so it is unaffected by a test driver draining the send queue. + */ + public int getRpcRequestsSentDelta() { + return rpcRequestsSent.delta(); + } + + /** + * Drains the requests the benchmark expects to be in-flight at the end of the invocation (the + * given {@code expectedRequest} API key, if any) and asserts the send queue is then empty. A + * non-empty queue means the client sent more requests than the benchmark accounts for. + */ + public void drainExpectedRequestsAndAssertEmpty(Optional<ApiKeys> expectedRequest) { + expectedRequest.ifPresent(apiKey -> channel.drainSentRequests(Optional.of(apiKey))); + if (channel.hasSentRequests()) { + throw new IllegalStateException( + "Unexpected outstanding requests at end of benchmark invocation: " + channel.drainSendQueue()); + } + } + + public int getQuorumStateWritesDelta() { + return quorumStateWrites.delta(); + } + + public int getQuorumStateReadsDelta() { + return quorumStateReads.delta(); + } + + /** + * Drains the responses the benchmark expects to be in-flight at the end of the invocation (the + * given {@code apiKey}, if any), counts them, then asserts no other responses remain. Returns the + * number of expected responses drained (0 if none are expected). A leftover response means the + * client sent more than the benchmark accounts for. + */ + public int maybeDrainSentRpcResponses(Optional<ApiKeys> apiKey) { + int expected = apiKey.map(key -> context.drainSentResponses(key).size()).orElse(0); + int remaining = context.drainAllSentResponses(); + if (remaining > 0) { + throw new IllegalStateException( + "Unexpected outstanding responses at end of benchmark invocation: " + remaining); + } + return expected; + } + + /** + * Tracks one cumulative mock counter as a delta against a baseline. {@link #reset()} snapshots the + * current value (so the next {@link #delta()} starts from zero), and {@link #delta()} returns the + * increase since the last reset/delta and advances the baseline. + */ + private static final class DrainableCounter { Review Comment: I like the idea of this class to reduce duplication. However, let's make sure we have unit tests for it. We may also want to have this be its own file so other tests can potentially use it. -- 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]
