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David Capwell commented on CASSANDRA-18507: ------------------------------------------- Thanks for all the hard work! merged to 4.0, 4.1, and trunk > Partial compaction can resurrect deleted data > --------------------------------------------- > > Key: CASSANDRA-18507 > URL: https://issues.apache.org/jira/browse/CASSANDRA-18507 > Project: Cassandra > Issue Type: Bug > Components: Local/Compaction > Reporter: Tobias Lindaaker > Assignee: Tobias Lindaaker > Priority: Normal > Fix For: 4.0.10, 4.1.2, 5.0 > > > If there isn't enough disk space available to compact all existing sstables, > Cassandra will attempt to perform a partial compaction by removing sstables > from the set of candidate sstables to be compacted, starting with the largest > one. It is possible that the sstable removed from the set of sstables to > compact contains data for which there are tombstones in another (more recent) > sstable. Since the overlaps between sstables is computed when the > {{CompactionController}} is created, and the {{CompactionController}} is > created before the removal of any sstables from the set of sstables to be > compacted this computed overlap will be outdated when checking which sstables > are covered by certain tombstones. This leads to the faulty conclusion that > the tombstones can be pruned during the compaction, causing the data to be > resurrected. > The issue is present in Cassandra 4.0 and 4.1. Cassandra 3.11 creates the > {{CompactionController}} after the set of sstables to compact has been > reduced, and is thus not affected. {{trunk}} does not appear to support > partial compactions at all, but instead refuses to compact when the disk is > full. > This regression appears to have been introduced by CASSANDRA-13068. -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org