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  1. Cassandra
  2. CASSANDRA-10979

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

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    • Severity:
      Normal

      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.

        Attachments

        1. 10979-2.1.txt
          3 kB
          Carl Yeksigian

          Activity

            People

            • Assignee:
              carlyeks Carl Yeksigian
              Reporter:
              autocracy Jeff Ferland
              Authors:
              Carl Yeksigian
              Reviewers:
              Marcus Eriksson
            • Votes:
              2 Vote for this issue
              Watchers:
              8 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: