[CASSANDRA-14207] Failed Compare and Swap in SASI's DataTracker#update Can Lead to Improper Reference Counting of SSTableIndex

• Type: Bug
• Status: Patch Available
• Priority: Normal
• Resolution: Unresolved
• Component/s: Feature/SASI
• Severity: Normal
• Assignee: Jordan West
• Reporter: Jordan West

Authors

Jordan West

Reviewers

Dinesh Joshi

• Created: 31/Jan/18 23:37
• Updated: 16/Apr/19 09:29

Description

A race between e.g. index redistribution and compaction (or memtable flushes and compaction) can cause the compare and swap of a new sasi.conf.View in sasi.conf.DataTracker#update to fail, leading to recreation of the view and improper reference counting of an SSTableIndex. This is because the side-effects (decrementing the reference count via SStableIndex#release) occur regardless of if the view is promoted to be the active view.  

Code: https://github.com/apache/cassandra/blob/cassandra-3.11.1/src/java/org/apache/cassandra/index/sasi/conf/DataTracker.java#L72-L78 

Attached logs and debug output show case where index redistribution and compaction race. This case was generated using the test provided in https://issues.apache.org/jira/browse/CASSANDRA-14055