satishd commented on code in PR #14004: URL: https://github.com/apache/kafka/pull/14004#discussion_r1268373435
########## storage/src/main/java/org/apache/kafka/server/log/remote/metadata/storage/RemoteLogLeaderEpochState.java: ########## @@ -100,17 +100,29 @@ void handleSegmentWithCopySegmentStartedState(RemoteLogSegmentId remoteLogSegmen void handleSegmentWithCopySegmentFinishedState(Long startOffset, RemoteLogSegmentId remoteLogSegmentId, Long leaderEpochEndOffset) { + // If there are duplicate segments uploaded due to leader-election, then mark them as unreferenced. + // Duplicate segments can be uploaded when the previous leader had tier-lags and the next leader uploads the + // segment for the same leader-epoch which is a super-set of previously uploaded segments. + // (eg) + // case-1: Duplicate segment + // L0 uploaded segment S0 with offsets 0-100 and L1 uploaded segment S1 with offsets 0-200. + // We will mark the segment S0 as duplicate and add it to unreferencedSegmentIds. + // case-2: Overlapping segments + // L0 uploaded segment S0 with offsets 10-90 and L1 uploaded segment S1 with offsets 5-100, S2-101-200, + // and so on. When the consumer request for segment with offset 95, it should get the segment S1 and not S0. + Map.Entry<Long, RemoteLogSegmentId> lastEntry = offsetToId.lastEntry(); + while (lastEntry != null && lastEntry.getKey() >= startOffset && highestLogOffset <= leaderEpochEndOffset) { Review Comment: Why would segment data for [151L,190L] is lost? This will be part of the next leader epoch state(viz 1) which should contain this segment. @kamalcph @Nickstery Am I missing anything here? -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org