github-advanced-security[bot] commented on code in PR #2898: URL: https://github.com/apache/jackrabbit-oak/pull/2898#discussion_r3241445674
########## oak-benchmarks/src/main/java/org/apache/jackrabbit/oak/benchmark/SegmentCacheTarBenchmark.java: ########## @@ -0,0 +1,557 @@ +/* + * 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.jackrabbit.oak.benchmark; + +import java.io.File; +import java.io.IOException; +import java.nio.file.Files; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.concurrent.ThreadLocalRandom; + +import javax.jcr.Repository; + +import org.apache.commons.io.FileUtils; +import org.apache.jackrabbit.oak.api.CommitFailedException; +import org.apache.jackrabbit.oak.api.jmx.CacheStatsMBean; +import org.apache.jackrabbit.oak.fixture.RepositoryFixture; +import org.apache.jackrabbit.oak.segment.SegmentCache.SegmentCachePolicy; +import org.apache.jackrabbit.oak.segment.SegmentId; +import org.apache.jackrabbit.oak.segment.SegmentNodeStoreBuilders; +import org.apache.jackrabbit.oak.segment.file.FileStore; +import org.apache.jackrabbit.oak.segment.file.FileStoreBuilder; +import org.apache.jackrabbit.oak.segment.file.InvalidFileStoreVersionException; +import org.apache.jackrabbit.oak.segment.file.ReadOnlyFileStore; +import org.apache.jackrabbit.oak.spi.commit.CommitInfo; +import org.apache.jackrabbit.oak.spi.commit.EmptyHook; +import org.apache.jackrabbit.oak.spi.state.NodeBuilder; + +/** + * Benchmark measuring actual wall-clock elapsed time per segment cache policy using + * real TAR file I/O. Unlike {@link SegmentCacheMemoizationBenchmark}, which uses mock + * segments (free TAR reads), cache misses here trigger actual disk reads — so a policy + * with a higher miss rate is measurably slower. + * + * <h3>Fixture note</h3> + * <p>The {@code RepositoryFixture} parameter only controls the JCR repository created by + * {@code AbstractTest} infrastructure. This benchmark creates its own {@link FileStore} in + * {@link #beforeSuite()} and always reads real TAR files, regardless of which fixture is + * passed. Use {@code Oak-MemoryNS} to avoid wasting disk space on an unused second store.</p> + * + * <h3>Access path</h3> + * <p>Every access calls {@link SegmentId#getSegment()}, which follows the full production + * chain: L1 memoization → on L1 miss: store → L2 cache → on L2 miss: loader (disk read). + * Stats decompose accesses into L1-hit%, L2-hit%, and TAR-read% (loader invocations).</p> + * + * <h3>Scenarios (all in {@code afterSuite})</h3> + * <ul> + * <li><b>Scenario 1 (Zipfian steady-state)</b> — live run driven by the AbstractTest + * timing loop; isolated per-policy elapsed time with full tier breakdown.</li> + * <li><b>Scenario 2 (drifting active set)</b> — sliding Zipfian window; Caffeine's + * W-TinyLFU admission gate rejects new-window entries (freq=0) against incumbents, + * triggering perpetual TAR-read loops. Caffeine is typically slower than Guava here.</li> + * <li><b>Scenario 3 (post-compaction cold-start)</b> — cache warmed on old-gen segments; + * traffic switches to new-gen (freq=0, LRU-cold). Per-epoch TAR% tracks warm-up speed.</li> + * </ul> + */ +public class SegmentCacheTarBenchmark extends AbstractTest { + + // ----- content generation ----- + private static final int N_NODES = 4_000; + private static final int N_BATCH = 1_000; + private static final int PROPERTY_KB = 10; + private static final int PROPERTY_BYTES = PROPERTY_KB * 1024; + + // ----- cache config: ~10 MB ≈ 40 data segments at 256 KB each ----- + private static final int CACHE_SIZE_MB = 10; + + // ----- Scenario 1: Zipfian steady-state ----- + private static final int BATCH_SIZE = Integer.getInteger("segment.batch.size", 500); + private static final int WARMUP_OPS = 5_000; + private static final int MEASURE_OPS = 50_000; + private static final double ZIPF_EXP = 1.0; + + // ----- Scenario 2: drifting active set ----- + private static final int WIDTH_2 = 100; // active window > cache capacity + private static final int DRIFT_2 = 5; // advance cursor every N ops + private static final double ZIPF_2_EXP = 0.5; // flatter → more entries compete for cache + private static final int WARMUP_2 = 20_000; + private static final int MEASURE_2 = 100_000; + private static final int EPOCH_OPS_2 = 10_000; + + // ----- Scenario 3: post-compaction cold-start ----- + private static final int WARMUP_3 = 20_000; // warm on old-gen + private static final int MEASURE_3 = 100_000; + private static final int EPOCH_OPS_3 = 10_000; + + private static final SegmentCachePolicy[] POLICIES = { + SegmentCachePolicy.CAFFEINE, + SegmentCachePolicy.CAFFEINE_WITH_EXPIRY, + SegmentCachePolicy.LIRS, + SegmentCachePolicy.GUAVA + }; + private static final String[] POLICY_NAMES = {"CAFFEINE", "CAFFEINE_WITH_EXPIRY", "LIRS", "GUAVA"}; + private static final int NUM_POLICIES = POLICIES.length; + + // ----- live-run state ----- + private File storeDir; + private int poolSize; + private double[] zipfCdf; + private ReadOnlyFileStore[] liveStores; + private SegmentId[][] liveIds; // liveIds[policy][segIdx] + private long[] liveTotalOps; // per-policy access counter for statsValues() + + @Override + public String toString() { + return "SegmentCacheTarBenchmark"; + } + + @Override + protected Repository[] createRepository(RepositoryFixture fixture) throws Exception { + return fixture.setUpCluster(1); + } + + /** + * Generates real TAR content, discovers the data-segment pool, and opens the + * per-policy live stores for the AbstractTest timing loop. + */ + @Override + protected void beforeSuite() throws Exception { + storeDir = Files.createTempDirectory("SegmentCacheTarBenchmark-").toFile(); Review Comment: ## SonarCloud / Temporary files should not be created in publicly writable directories <!--SONAR_ISSUE_KEY:AZ4miz5TrfNQ6yOhD_tx-->Make sure publicly writable directories are used safely here. <p>See more on <a href="https://sonarcloud.io/project/issues?id=org.apache.jackrabbit%3Ajackrabbit-oak&issues=AZ4miz5TrfNQ6yOhD_tx&open=AZ4miz5TrfNQ6yOhD_tx&pullRequest=2898";>SonarQube Cloud</a></p> [Show more details](https://github.com/apache/jackrabbit-oak/security/code-scanning/192) -- This is an automated message from the Apache Git Service. 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