[CASSANDRA-10979] LCS doesn't do L0 STC on new tables while an L0->L1 compaction is in progress

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.1.14, 2.2.5, 3.0.3, 3.3
• Component/s: Local/Compaction
• Labels: compaction lcs leveled

Environment

2.1.11 / 4.8.3 DSE.

• Severity: Normal
• Assignee: Carl Yeksigian
• Reporter: Jeff Ferland

Authors

Carl Yeksigian

Reviewers

Marcus Eriksson

• Created: 07/Jan/16 00:29
• Updated: 16/Apr/19 09:30
• Resolved: 22/Jan/16 06:36

Description

Reading code from https://github.com/apache/cassandra/blob/cassandra-2.1/src/java/org/apache/cassandra/db/compaction/LeveledManifest.java and comparing with behavior shown in https://gist.github.com/autocracy/c95aca6b00e42215daaf, the following happens:

Score for L1,L2,and L3 is all < 1 (paste shows 20/10 and 200/100, due to incremental repair).

Relevant code from here is

if (Sets.intersection(l1overlapping, compacting).size() > 0)
return Collections.emptyList();

Since there will be overlap between what is compacting and L1 (in my case, pushing over 1,000 tables in to L1 from L0 SCTS), I get a pile up of 1,000 smaller tables in L0 while awaiting the transition from L0 to L1 and destroy my performance.

Requested outcome is to continue to perform SCTS on non-compacting L0 tables.