m1a2st commented on code in PR #23380: URL: https://github.com/apache/kafka/pull/23380#discussion_r3947451378
########## storage/src/test/java/org/apache/kafka/storage/internals/epoch/LeaderEpochFileCacheTest.java: ########## @@ -0,0 +1,565 @@ +/* + * 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.storage.internals.epoch; + +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.server.util.MockTime; +import org.apache.kafka.storage.internals.checkpoint.LeaderEpochCheckpointFile; +import org.apache.kafka.storage.internals.log.EpochEntry; +import org.apache.kafka.storage.internals.log.LogDirFailureChannel; +import org.apache.kafka.test.TestUtils; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +import java.io.File; +import java.io.IOException; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.OptionalInt; + +import static org.apache.kafka.common.requests.OffsetsForLeaderEpochResponse.UNDEFINED_EPOCH; +import static org.apache.kafka.common.requests.OffsetsForLeaderEpochResponse.UNDEFINED_EPOCH_OFFSET; +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; +import static org.junit.jupiter.api.Assertions.assertEquals; + +/** + * Unit test for the LeaderEpochFileCache. + */ +public class LeaderEpochFileCacheTest { + private final TopicPartition tp = new TopicPartition("TestTopic", 5); + + private LeaderEpochCheckpointFile checkpoint; + private LeaderEpochFileCache cache; + + @BeforeEach + public void setup() throws IOException { + MockTime mockTime = new MockTime(); + checkpoint = new LeaderEpochCheckpointFile(TestUtils.tempFile(), new LogDirFailureChannel(1)); + cache = new LeaderEpochFileCache(tp, checkpoint, mockTime.scheduler); + } + + @Test + public void testPreviousEpoch() { + assertEquals(OptionalInt.empty(), cache.previousEpoch()); + + cache.assign(2, 10); + assertEquals(OptionalInt.empty(), cache.previousEpoch()); + + cache.assign(4, 15); + assertEquals(OptionalInt.of(2), cache.previousEpoch()); + + cache.assign(10, 20); + assertEquals(OptionalInt.of(4), cache.previousEpoch()); + + cache.truncateFromEndAsyncFlush(18); + assertEquals(OptionalInt.of(2), cache.previousEpoch()); + } + + @Test + public void shouldAddEpochAndMessageOffsetToCache() { + cache.assign(2, 10); + long logEndOffset = 11; + + assertEquals(Optional.of(2), cache.latestEpoch()); + assertEquals(new EpochEntry(2, 10), cache.epochEntries().get(0)); + assertEquals(Map.entry(2, logEndOffset), cache.endOffsetFor(2, logEndOffset)); + } + + @Test + public void shouldReturnLogEndOffsetIfLatestEpochRequested() { + cache.assign(2, 11); + cache.assign(2, 12); + long logEndOffset = 14; + + assertEquals(Map.entry(2, logEndOffset), cache.endOffsetFor(2, logEndOffset)); + } + + @Test + public void shouldReturnUndefinedOffsetIfUndefinedEpochRequested() { + Map.Entry<Integer, Long> expectedEpochEndOffset = Map.entry(UNDEFINED_EPOCH, UNDEFINED_EPOCH_OFFSET); + + cache.assign(2, 11); + cache.assign(3, 12); + + Map.Entry<Integer, Long> epochAndOffsetFor = cache.endOffsetFor(UNDEFINED_EPOCH, 0L); + + assertEquals( + expectedEpochEndOffset, + epochAndOffsetFor, + "Expected undefined epoch and offset if undefined epoch requested. Cache not empty."); + } + + @Test + public void shouldNotOverwriteLogEndOffsetForALeaderEpochOnceItHasBeenAssigned() { + long logEndOffset = 9; + + cache.assign(2, logEndOffset); + + cache.assign(2, 10); + + assertEquals(logEndOffset, cache.epochEntries().get(0).startOffset()); + assertEquals(List.of(new EpochEntry(2, 9)), cache.epochEntries()); + } Review Comment: `shouldNotOverwriteLogEndOffsetForALeaderEpochOnceItHasBeenAssigned` and `shouldNotOverwriteOffsetForALeaderEpochOnceItHasBeenAssigned` verify the same behavior: assign() should not overwrite the startOffset for an epoch that has already been assigned. The first test name mentions LogEndOffset, but that is misleading, since logEndOffset is only passed as the startOffset argument to assign() and is unrelated to the log end offset concept. Could we merge these into a single test? ########## storage/src/test/java/org/apache/kafka/storage/internals/epoch/LeaderEpochFileCacheTest.java: ########## @@ -0,0 +1,565 @@ +/* + * 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.storage.internals.epoch; + +import org.apache.kafka.common.TopicPartition; +import org.apache.kafka.server.util.MockTime; +import org.apache.kafka.storage.internals.checkpoint.LeaderEpochCheckpointFile; +import org.apache.kafka.storage.internals.log.EpochEntry; +import org.apache.kafka.storage.internals.log.LogDirFailureChannel; +import org.apache.kafka.test.TestUtils; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +import java.io.File; +import java.io.IOException; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.OptionalInt; + +import static org.apache.kafka.common.requests.OffsetsForLeaderEpochResponse.UNDEFINED_EPOCH; +import static org.apache.kafka.common.requests.OffsetsForLeaderEpochResponse.UNDEFINED_EPOCH_OFFSET; +import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; +import static org.junit.jupiter.api.Assertions.assertEquals; + +/** + * Unit test for the LeaderEpochFileCache. + */ +public class LeaderEpochFileCacheTest { + private final TopicPartition tp = new TopicPartition("TestTopic", 5); + + private LeaderEpochCheckpointFile checkpoint; + private LeaderEpochFileCache cache; + + @BeforeEach + public void setup() throws IOException { + MockTime mockTime = new MockTime(); + checkpoint = new LeaderEpochCheckpointFile(TestUtils.tempFile(), new LogDirFailureChannel(1)); + cache = new LeaderEpochFileCache(tp, checkpoint, mockTime.scheduler); + } + + @Test + public void testPreviousEpoch() { + assertEquals(OptionalInt.empty(), cache.previousEpoch()); + + cache.assign(2, 10); + assertEquals(OptionalInt.empty(), cache.previousEpoch()); + + cache.assign(4, 15); + assertEquals(OptionalInt.of(2), cache.previousEpoch()); + + cache.assign(10, 20); + assertEquals(OptionalInt.of(4), cache.previousEpoch()); + + cache.truncateFromEndAsyncFlush(18); + assertEquals(OptionalInt.of(2), cache.previousEpoch()); + } + + @Test + public void shouldAddEpochAndMessageOffsetToCache() { + cache.assign(2, 10); + long logEndOffset = 11; + + assertEquals(Optional.of(2), cache.latestEpoch()); + assertEquals(new EpochEntry(2, 10), cache.epochEntries().get(0)); + assertEquals(Map.entry(2, logEndOffset), cache.endOffsetFor(2, logEndOffset)); + } + + @Test + public void shouldReturnLogEndOffsetIfLatestEpochRequested() { + cache.assign(2, 11); + cache.assign(2, 12); + long logEndOffset = 14; + + assertEquals(Map.entry(2, logEndOffset), cache.endOffsetFor(2, logEndOffset)); + } + + @Test + public void shouldReturnUndefinedOffsetIfUndefinedEpochRequested() { + Map.Entry<Integer, Long> expectedEpochEndOffset = Map.entry(UNDEFINED_EPOCH, UNDEFINED_EPOCH_OFFSET); + + cache.assign(2, 11); + cache.assign(3, 12); + + Map.Entry<Integer, Long> epochAndOffsetFor = cache.endOffsetFor(UNDEFINED_EPOCH, 0L); + + assertEquals( + expectedEpochEndOffset, + epochAndOffsetFor, + "Expected undefined epoch and offset if undefined epoch requested. Cache not empty."); + } + + @Test + public void shouldNotOverwriteLogEndOffsetForALeaderEpochOnceItHasBeenAssigned() { + long logEndOffset = 9; + + cache.assign(2, logEndOffset); + + cache.assign(2, 10); + + assertEquals(logEndOffset, cache.epochEntries().get(0).startOffset()); + assertEquals(List.of(new EpochEntry(2, 9)), cache.epochEntries()); + } + + @Test + public void shouldEnforceMonotonicallyIncreasingStartOffsets() { + cache.assign(2, 9); + + cache.assign(3, 9); + + assertEquals(List.of(new EpochEntry(3, 9)), cache.epochEntries()); + } + + @Test + public void shouldNotOverwriteOffsetForALeaderEpochOnceItHasBeenAssigned() { + cache.assign(2, 6); + + cache.assign(2, 10); + + assertEquals(6, cache.epochEntries().get(0).startOffset()); + } + + @Test + public void shouldReturnUnsupportedIfNoEpochRecorded() { + assertEquals(Map.entry(UNDEFINED_EPOCH, UNDEFINED_EPOCH_OFFSET), cache.endOffsetFor(0, 0L)); + } + + @Test + public void shouldReturnUnsupportedIfNoEpochRecordedAndUndefinedEpochRequested() { + Map.Entry<Integer, Long> offsetFor = cache.endOffsetFor(UNDEFINED_EPOCH, 73); + + assertEquals( + Map.entry(UNDEFINED_EPOCH, UNDEFINED_EPOCH_OFFSET), + offsetFor, + "Expected undefined epoch and offset if undefined epoch requested. Empty cache."); + } + + @Test + public void shouldReturnFirstEpochIfRequestedEpochLessThanFirstEpoch() { + cache.assign(5, 11); + cache.assign(6, 12); + cache.assign(7, 13); + + Map.Entry<Integer, Long> epochAndOffset = cache.endOffsetFor(4, 0L); + + assertEquals(Map.entry(4, 11L), epochAndOffset); + } + + @Test + public void shouldTruncateIfMatchingEpochButEarlierStartingOffset() { + cache.assign(5, 11); + cache.assign(6, 12); + cache.assign(7, 13); + + cache.assign(7, 12); + + assertEquals(Map.entry(5, 12L), cache.endOffsetFor(5, 0L)); + assertEquals(Map.entry(5, 12L), cache.endOffsetFor(6, 0L)); + } + + @Test + public void shouldGetFirstOffsetOfSubsequentEpochWhenOffsetRequestedForPreviousEpoch() { + cache.assign(1, 11); + cache.assign(1, 12); + cache.assign(2, 13); + cache.assign(2, 14); + cache.assign(3, 15); + cache.assign(3, 16); + + assertEquals(Map.entry(2, 15L), cache.endOffsetFor(2, 17)); + } + + @Test + public void shouldReturnNextAvailableEpochIfThereIsNoExactEpochForTheOneRequested() { + cache.assign(0, 10); + cache.assign(2, 13); + cache.assign(4, 17); + + assertEquals(Map.entry(0, 13L), cache.endOffsetFor(1, 0L)); + assertEquals(Map.entry(2, 17L), cache.endOffsetFor(2, 0L)); + assertEquals(Map.entry(2, 17L), cache.endOffsetFor(3, 0L)); + } + + @Test + public void shouldNotUpdateEpochAndStartOffsetIfItDidNotChange() { + cache.assign(2, 6); + cache.assign(2, 7); + + assertEquals(1, cache.epochEntries().size()); + assertEquals(new EpochEntry(2, 6), cache.epochEntries().get(0)); + } + + @Test + public void shouldReturnInvalidOffsetIfEpochIsRequestedWhichIsNotCurrentlyTracked() { + cache.assign(2, 100); + + assertEquals(Map.entry(UNDEFINED_EPOCH, UNDEFINED_EPOCH_OFFSET), cache.endOffsetFor(3, 100)); + } + + @Test + public void shouldSupportEpochsThatDoNotStartFromZero() { + cache.assign(2, 6); + long logEndOffset = 7; + + assertEquals(Map.entry(2, logEndOffset), cache.endOffsetFor(2, logEndOffset)); + assertEquals(1, cache.epochEntries().size()); + assertEquals(new EpochEntry(2, 6), cache.epochEntries().get(0)); + } + + @Test + public void shouldPersistEpochsBetweenInstances() throws IOException { + String checkpointPath = TestUtils.tempFile().getAbsolutePath(); + LeaderEpochCheckpointFile checkpoint = new LeaderEpochCheckpointFile( + new File(checkpointPath), + new LogDirFailureChannel(1)); + + LeaderEpochFileCache cache = new LeaderEpochFileCache(tp, checkpoint, new MockTime().scheduler); + cache.assign(2, 6); + + LeaderEpochCheckpointFile checkpoint2 = new LeaderEpochCheckpointFile( + new File(checkpointPath), + new LogDirFailureChannel(1)); + LeaderEpochFileCache cache2 = new LeaderEpochFileCache(tp, checkpoint2, new MockTime().scheduler); + + assertEquals(1, cache2.epochEntries().size()); + assertEquals(new EpochEntry(2, 6), cache2.epochEntries().get(0)); + } + + @Test + public void shouldEnforceMonotonicallyIncreasingEpochs() { + cache.assign(1, 5); + cache.assign(2, 6); + cache.assign(1, 7); Review Comment: We should keep the original comment ``` // When we update an epoch in the past with a different offset, the log has already reached // an inconsistent state. Our options are either to raise an error, ignore the new append, // or truncate the cached epochs to the point of conflict. We take this latter approach in // order to guarantee that epochs and offsets in the cache increase monotonically, which makes // the search logic simpler to reason about. ``` -- 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]
