kamalcph commented on code in PR #16884: URL: https://github.com/apache/kafka/pull/16884#discussion_r2299738443
########## core/src/test/scala/unit/kafka/server/AbstractFetcherThreadTest.scala: ########## @@ -1180,4 +1180,562 @@ class AbstractFetcherThreadTest { fetcher.processFetchRequest(partitionData, fetchRequestOpt) assertEquals(0, replicaState.logEndOffset, "FetchResponse should be ignored when leader epoch does not match") } + + private def emptyReplicaState(rlmEnabled: Boolean, partition: TopicPartition, fetcher: MockFetcherThread) = { + // Follower begins with an empty log + val replicaState = PartitionState(Seq(), leaderEpoch = 0, highWatermark = 0L, rlmEnabled = rlmEnabled) + fetcher.setReplicaState(partition, replicaState) + fetcher.addPartitions(Map(partition -> initialFetchState(topicIds.get(partition.topic), fetchOffset = 0, leaderEpoch = 0))) + replicaState + } + + /** + * Test: Empty Follower Fetch with TieredStorage Disabled and Leader LogStartOffset = 0 + * + * Purpose: + * - Simulate a leader with logs starting at offset 0 and validate how the follower + * behaves when TieredStorage is disabled. + * + * Conditions: + * - TieredStorage: **Disabled** + * - Leader LogStartOffset: **0** + * + * Scenario: + * - The leader starts with a log at offset 0, containing three record batches offset at 0, 150, and 199. + * - The follower begins fetching, and we validate the correctness of its replica state as it fetches. + * + * Expected Outcomes: + * 1. The follower fetch state should transition to `FETCHING` initially. + * 2. After the first poll, one record batch is fetched. + * 3. After subsequent polls, the entire leader log is fetched: + * - Replica log size: 3 + * - Replica LogStartOffset: 0 + * - Replica LogEndOffset: 200 + * - Replica HighWatermark: 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageDisabledLeaderLogStartOffsetZero(): Unit = { + val rlmEnabled = false + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 0 + mkBatch(baseOffset = 0, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(1, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(1, replicaState.logEndOffset) + assertEquals(Some(1), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 2) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Disabled and Leader LogStartOffset != 0 + * + * Purpose: + * - Validate follower behavior when the leader's log starts at a non-zero offset (10). + * + * Conditions: + * - TieredStorage: **Disabled** + * - Leader LogStartOffset: **10** + * + * Scenario: + * - The leader log starts at offset 10 with batches at 10, 150, and 199. + * - The follower starts fetching from offset 10. + * + * Expected Outcomes: + * 1. The follower's initial log is empty. + * 2. Replica offsets after polls: + * - LogStartOffset = 10 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageDisabledLeaderLogStartOffsetNonZero(): Unit = { + val rlmEnabled = false + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 10 + mkBatch(baseOffset = 10, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + // Follower gets out-of-range error (no messages received), fetch offset is updated from 0 to 10 + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset = 0, and No Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled and validate follower fetching behavior when the leader + * log starts at 0 and no segments have been uploaded or deleted locally. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0** + * - Leader LocalLogStartOffset: **0** (No local segments deleted). + * + * Scenario: + * - The leader log contains three record batches at offsets 0, 150, and 199. + * - The follower starts fetching from offset 0. + * + * Expected Outcomes: + * 1. The replica log accurately reflects the leader's log: + * - LogStartOffset = 0 + * - LocalLogStartOffset = 0 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroNoLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 0 + mkBatch(baseOffset = 0, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(1, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(0, replicaState.localLogStartOffset) + assertEquals(1, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + assertEquals(Some(1), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 2) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(0, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset = 0, and Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled with some segments uploaded and deleted locally, causing + * a difference between the leader's LogStartOffset (0) and LocalLogStartOffset (> 0). + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0** + * - Leader LocalLogStartOffset: **100** (Some segments deleted locally). + * + * Scenario: + * - The leader log starts at offset 0 but the local leader log starts at offset 100. + * - The follower fetch operation begins from offset 0. + * + * Expected Outcomes: + * 1. After offset adjustments for local deletions: + * - LogStartOffset = 0 + * - LocalLogStartOffset = 100 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroWithLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + leaderState.logStartOffset = 0 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(100, replicaState.logEndOffset) + assertEquals(Some(100), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset != 0, and No Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled and validate follower fetch behavior when the leader's log + * starts at a non-zero offset and no local deletions have occurred. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **10** + * - Leader LocalLogStartOffset: **10** (No deletions). + * + * Scenario: + * - The leader log starts at offset 10 with batches at 10, 150, and 199. + * - The follower starts fetching from offset 10. + * + * Expected Outcomes: + * 1. After fetching, the replica log matches the leader: + * - LogStartOffset = 10 + * - LocalLogStartOffset = 10 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetNonZeroNoLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 10 + mkBatch(baseOffset = 10, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled, + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset != 0, and Local Deletions + * + * Purpose: + * - Validate follower adjustments when the leader has log deletions causing + * LocalLogStartOffset > LogStartOffset. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **10** + * - Leader LocalLogStartOffset: **100** (All older segments deleted locally). + * + * Scenario: + * - The leader log starts at offset 10 but the local log starts at offset 100. + * - The follower fetch starts at offset 10 but adjusts for local deletions. + * + * Expected Outcomes: + * 1. Initial fetch offset adjustments: + * - First adjustment: LogEndOffset = 10 (after offset-out-of-range error) + * - Second adjustment: LogEndOffset = 100 (after offset-moved-to-tiered-storage error) + * 2. After successful fetches: + * - 3 record batches fetched + * - LogStartOffset = 10 + * - LocalLogStartOffset = 100 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetNonZeroWithLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled, + ) + leaderState.logStartOffset = 10 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + // On offset-out-of-range error, fetch offset is updated + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + fetcher.doWork() + // On offset-moved-to-tiered-storage error, fetch offset is updated + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(100, replicaState.logEndOffset) + assertEquals(Some(100), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, All Local Segments Deleted + * + * Purpose: + * - Handle scenarios where all local segments have been deleted: + * - LocalLogStartOffset > LogStartOffset. + * - LocalLogStartOffset = LogEndOffset. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0 or > 0** + * - Leader LocalLogStartOffset: Leader LogEndOffset (all segments deleted locally). + * + * Expected Outcomes: + * 1. Follower state is adjusted to reflect local deletions: + * - LocalLogStartOffset = LogEndOffset. + * - No new data remains to fetch. + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroAllLocalSegmentsDeleted(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 151L, + rlmEnabled = rlmEnabled + ) + leaderState.logStartOffset = 0 + // Set Local Log Start Offset to Log End Offset + leaderState.localLogStartOffset = 151 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + + // On offset-moved-to-tiered-storage error, fetch offset is updated + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(151, replicaState.localLogStartOffset) + assertEquals(151, replicaState.logEndOffset) + assertEquals(151, replicaState.highWatermark) + assertEquals(Some(151), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Call once again to see if new data is received + fetcher.doWork() + // No metadata update expected + assertEquals(0, replicaState.log.size) + assertEquals(151, replicaState.localLogStartOffset) Review Comment: shall we also assert logStartOffset? ########## core/src/test/scala/unit/kafka/server/AbstractFetcherThreadTest.scala: ########## @@ -1180,4 +1180,562 @@ class AbstractFetcherThreadTest { fetcher.processFetchRequest(partitionData, fetchRequestOpt) assertEquals(0, replicaState.logEndOffset, "FetchResponse should be ignored when leader epoch does not match") } + + private def emptyReplicaState(rlmEnabled: Boolean, partition: TopicPartition, fetcher: MockFetcherThread) = { + // Follower begins with an empty log + val replicaState = PartitionState(Seq(), leaderEpoch = 0, highWatermark = 0L, rlmEnabled = rlmEnabled) + fetcher.setReplicaState(partition, replicaState) + fetcher.addPartitions(Map(partition -> initialFetchState(topicIds.get(partition.topic), fetchOffset = 0, leaderEpoch = 0))) + replicaState + } + + /** + * Test: Empty Follower Fetch with TieredStorage Disabled and Leader LogStartOffset = 0 + * + * Purpose: + * - Simulate a leader with logs starting at offset 0 and validate how the follower + * behaves when TieredStorage is disabled. + * + * Conditions: + * - TieredStorage: **Disabled** + * - Leader LogStartOffset: **0** + * + * Scenario: + * - The leader starts with a log at offset 0, containing three record batches offset at 0, 150, and 199. + * - The follower begins fetching, and we validate the correctness of its replica state as it fetches. + * + * Expected Outcomes: + * 1. The follower fetch state should transition to `FETCHING` initially. + * 2. After the first poll, one record batch is fetched. + * 3. After subsequent polls, the entire leader log is fetched: + * - Replica log size: 3 + * - Replica LogStartOffset: 0 + * - Replica LogEndOffset: 200 + * - Replica HighWatermark: 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageDisabledLeaderLogStartOffsetZero(): Unit = { + val rlmEnabled = false + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 0 + mkBatch(baseOffset = 0, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(1, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(1, replicaState.logEndOffset) + assertEquals(Some(1), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 2) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Disabled and Leader LogStartOffset != 0 + * + * Purpose: + * - Validate follower behavior when the leader's log starts at a non-zero offset (10). + * + * Conditions: + * - TieredStorage: **Disabled** + * - Leader LogStartOffset: **10** + * + * Scenario: + * - The leader log starts at offset 10 with batches at 10, 150, and 199. + * - The follower starts fetching from offset 10. + * + * Expected Outcomes: + * 1. The follower's initial log is empty. + * 2. Replica offsets after polls: + * - LogStartOffset = 10 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageDisabledLeaderLogStartOffsetNonZero(): Unit = { + val rlmEnabled = false + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 10 + mkBatch(baseOffset = 10, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + // Follower gets out-of-range error (no messages received), fetch offset is updated from 0 to 10 + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset = 0, and No Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled and validate follower fetching behavior when the leader + * log starts at 0 and no segments have been uploaded or deleted locally. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0** + * - Leader LocalLogStartOffset: **0** (No local segments deleted). + * + * Scenario: + * - The leader log contains three record batches at offsets 0, 150, and 199. + * - The follower starts fetching from offset 0. + * + * Expected Outcomes: + * 1. The replica log accurately reflects the leader's log: + * - LogStartOffset = 0 + * - LocalLogStartOffset = 0 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroNoLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 0 + mkBatch(baseOffset = 0, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(1, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(0, replicaState.localLogStartOffset) + assertEquals(1, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + assertEquals(Some(1), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 2) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(0, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset = 0, and Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled with some segments uploaded and deleted locally, causing + * a difference between the leader's LogStartOffset (0) and LocalLogStartOffset (> 0). + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0** + * - Leader LocalLogStartOffset: **100** (Some segments deleted locally). + * + * Scenario: + * - The leader log starts at offset 0 but the local leader log starts at offset 100. + * - The follower fetch operation begins from offset 0. + * + * Expected Outcomes: + * 1. After offset adjustments for local deletions: + * - LogStartOffset = 0 + * - LocalLogStartOffset = 100 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroWithLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled + ) + leaderState.logStartOffset = 0 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(100, replicaState.logEndOffset) + assertEquals(Some(100), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(0, replicaState.logStartOffset) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset != 0, and No Local Deletions + * + * Purpose: + * - Simulate TieredStorage enabled and validate follower fetch behavior when the leader's log + * starts at a non-zero offset and no local deletions have occurred. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **10** + * - Leader LocalLogStartOffset: **10** (No deletions). + * + * Scenario: + * - The leader log starts at offset 10 with batches at 10, 150, and 199. + * - The follower starts fetching from offset 10. + * + * Expected Outcomes: + * 1. After fetching, the replica log matches the leader: + * - LogStartOffset = 10 + * - LocalLogStartOffset = 10 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetNonZeroNoLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LogStartOffset = LocalLogStartOffset = 10 + mkBatch(baseOffset = 10, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled, + ) + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset != 0, and Local Deletions + * + * Purpose: + * - Validate follower adjustments when the leader has log deletions causing + * LocalLogStartOffset > LogStartOffset. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **10** + * - Leader LocalLogStartOffset: **100** (All older segments deleted locally). + * + * Scenario: + * - The leader log starts at offset 10 but the local log starts at offset 100. + * - The follower fetch starts at offset 10 but adjusts for local deletions. + * + * Expected Outcomes: + * 1. Initial fetch offset adjustments: + * - First adjustment: LogEndOffset = 10 (after offset-out-of-range error) + * - Second adjustment: LogEndOffset = 100 (after offset-moved-to-tiered-storage error) + * 2. After successful fetches: + * - 3 record batches fetched + * - LogStartOffset = 10 + * - LocalLogStartOffset = 100 + * - LogEndOffset = 200 + * - HighWatermark = 199 + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetNonZeroWithLocalDeletions(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + mkBatch(baseOffset = 199, leaderEpoch = 0, new SimpleRecord("e".getBytes)) + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 199L, + rlmEnabled = rlmEnabled, + ) + leaderState.logStartOffset = 10 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + // On offset-out-of-range error, fetch offset is updated + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + fetcher.doWork() + // On offset-moved-to-tiered-storage error, fetch offset is updated + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(100, replicaState.logEndOffset) + assertEquals(Some(100), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Only 1 record batch is returned after a poll so calling 'n' number of times to get the desired result. + for (_ <- 1 to 3) fetcher.doWork() + assertEquals(3, replicaState.log.size) + assertEquals(10, replicaState.logStartOffset) + assertEquals(100, replicaState.localLogStartOffset) + assertEquals(200, replicaState.logEndOffset) + assertEquals(199, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, All Local Segments Deleted + * + * Purpose: + * - Handle scenarios where all local segments have been deleted: + * - LocalLogStartOffset > LogStartOffset. + * - LocalLogStartOffset = LogEndOffset. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **0 or > 0** + * - Leader LocalLogStartOffset: Leader LogEndOffset (all segments deleted locally). + * + * Expected Outcomes: + * 1. Follower state is adjusted to reflect local deletions: + * - LocalLogStartOffset = LogEndOffset. + * - No new data remains to fetch. + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetZeroAllLocalSegmentsDeleted(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 151L, + rlmEnabled = rlmEnabled + ) + leaderState.logStartOffset = 0 + // Set Local Log Start Offset to Log End Offset + leaderState.localLogStartOffset = 151 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + + // On offset-moved-to-tiered-storage error, fetch offset is updated + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(151, replicaState.localLogStartOffset) + assertEquals(151, replicaState.logEndOffset) + assertEquals(151, replicaState.highWatermark) + assertEquals(Some(151), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Call once again to see if new data is received + fetcher.doWork() + // No metadata update expected + assertEquals(0, replicaState.log.size) + assertEquals(151, replicaState.localLogStartOffset) + assertEquals(151, replicaState.logEndOffset) + assertEquals(151, replicaState.highWatermark) + } + + /** + * Test: Empty Follower Fetch with TieredStorage Enabled, Leader LogStartOffset != 0, and All Local Segments Deleted + * + * Purpose: + * - Validate follower behavior when TieredStorage is enabled, the leader's log starts at a non-zero offset, + * and all local log segments have been deleted. + * + * Conditions: + * - TieredStorage: **Enabled** + * - Leader LogStartOffset: **10** + * - Leader LocalLogStartOffset: **151** (all older segments deleted locally). + * + * Scenario: + * - The leader log contains record batches from offset 100, but all local segments up to offset 151 are deleted. + * - The follower starts at LogStartOffset = 10 and adjusts for local segment deletions. + * + * Expected Outcomes: + * 1. Follower detects offset adjustments due to local deletions: + * - LogStartOffset remains 10. + * - LocalLogStartOffset updates to 151. + * - LogEndOffset updates to 151. + * 2. HighWatermark aligns with the leader (151). + * 3. No new data is fetched since all relevant segments are deleted. + */ + @Test + def testEmptyFollowerFetchTieredStorageEnabledLeaderLogStartOffsetNonZeroAllLocalSegmentsDeleted(): Unit = { + val rlmEnabled = true + val partition = new TopicPartition("topic1", 0) + val mockLeaderEndpoint = new MockLeaderEndPoint(version = version) + val mockTierStateMachine = new MockTierStateMachine(mockLeaderEndpoint) + val fetcher = new MockFetcherThread(mockLeaderEndpoint, mockTierStateMachine) + + val replicaState = emptyReplicaState(rlmEnabled, partition, fetcher) + + val leaderLog = Seq( + // LocalLogStartOffset = 100 + mkBatch(baseOffset = 100, leaderEpoch = 0, new SimpleRecord("c".getBytes)), + mkBatch(baseOffset = 150, leaderEpoch = 0, new SimpleRecord("d".getBytes)), + ) + + val leaderState = PartitionState( + leaderLog, + leaderEpoch = 0, + highWatermark = 151L, + rlmEnabled = rlmEnabled + ) + leaderState.logStartOffset = 10 + // Set Local Log Start Offset to Log End Offset + leaderState.localLogStartOffset = 151 + fetcher.mockLeader.setLeaderState(partition, leaderState) + fetcher.mockLeader.setReplicaPartitionStateCallback(fetcher.replicaPartitionState) + + fetcher.doWork() + + // On offset-out-of-range error, fetch offset is updated + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(10, replicaState.localLogStartOffset) + assertEquals(10, replicaState.logEndOffset) + assertEquals(Some(10), fetcher.fetchState(partition).map(_.fetchOffset())) + + // On offset-moved-to-tiered-storage error, fetch offset is updated + fetcher.doWork() + assertEquals(Option(ReplicaState.FETCHING), fetcher.fetchState(partition).map(_.state)) + assertEquals(0, replicaState.log.size) + assertEquals(151, replicaState.localLogStartOffset) + assertEquals(151, replicaState.logEndOffset) + assertEquals(151, replicaState.highWatermark) + assertEquals(Some(151), fetcher.fetchState(partition).map(_.fetchOffset())) + + // Call once again to see if new data is received + fetcher.doWork() + // No metadata update expected + assertEquals(0, replicaState.log.size) Review Comment: shall we also assert logStartOffset? -- This is an automated message from the Apache Git Service. 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