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Szymon Miezal commented on CASSANDRA-18824: ------------------------------------------- Going back to it after a while, I have prepared new branches, 3.1 - 3.11 commits contain backport plus a test adjustment, 4.0 - trunk commits contain only the test adjustment which makes it independent from the other test. * [https://github.com/szymon-miezal/cassandra/commit/e3b6bb2761dceeb09b2a4142486cdc4dfbb79edf] (3.0) * [https://github.com/szymon-miezal/cassandra/commit/bde29b98a96dd6e7923ad76d4f2421cfc3f9435f] (3.11) * [https://github.com/szymon-miezal/cassandra/commit/131cd3180da8668168bfcea0bcbec39627fef0ab] (4.0) * [https://github.com/szymon-miezal/cassandra/commit/5db9873af77ba1669af43ac9f6d1e4d3a5cbffc5] (4.1) * [https://github.com/szymon-miezal/cassandra/commit/e34e95011265788b9d61786ee4c54cd71f86b4b9] (5.0) * [https://github.com/szymon-miezal/cassandra/commit/4c41cb72f6917df00d17436b7342e21a5ec8766e] (trunk) I am not sure whether modifying _CHANGES.txt_ file was what should be done at this stage or during merging. > Backport CASSANDRA-16418: Cleanup behaviour during node decommission caused > missing replica > ------------------------------------------------------------------------------------------- > > Key: CASSANDRA-18824 > URL: https://issues.apache.org/jira/browse/CASSANDRA-18824 > Project: Cassandra > Issue Type: Bug > Components: Consistency/Bootstrap and Decommission > Reporter: Szymon Miezal > Assignee: Szymon Miezal > Priority: Normal > Fix For: 3.0.x, 3.11.x > > > Node decommission triggers data transfer to other nodes. While this transfer > is in progress, > receiving nodes temporarily hold token ranges in a pending state. However, > the cleanup process currently doesn't consider these pending ranges when > calculating token ownership. > As a consequence, data that is already stored in sstables gets inadvertently > cleaned up. > STR: > * Create two node cluster > * Create keyspace with RF=1 > * Insert sample data (assert data is available when querying both nodes) > * Start decommission process of node 1 > * Start running cleanup in a loop on node 2 until decommission on node 1 > finishes > * Verify of all rows are in the cluster - it will fail as the previous step > removed some of the rows > It seems that the cleanup process does not take into account the pending > ranges, it uses only the local ranges - > [https://github.com/apache/cassandra/blob/caad2f24f95b494d05c6b5d86a8d25fbee58d7c2/src/java/org/apache/cassandra/db/compaction/CompactionManager.java#L466]. > There are two solutions to the problem. > One would be to change the cleanup process in a way that it start taking > pending ranges into account. Even thought it might sound tempting at first it > will require involving changes and a lot of testing effort. > Alternatively we could interrupt/prevent the cleanup process from running > when any pending range on a node is detected. That sounds like a reasonable > alternative to the problem and something that is relatively easy to implement. > The bug has been already fixed in 4.x with CASSANDRA-16418, the goal of this > ticket is to backport it to 3.x. -- 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