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From "T Jake Luciani (JIRA)" <>
Subject [jira] [Created] (CASSANDRA-7272) Add "Major" Compaction to LCS
Date Tue, 20 May 2014 13:24:38 GMT
T Jake Luciani created CASSANDRA-7272:

             Summary: Add "Major" Compaction to LCS 
                 Key: CASSANDRA-7272
             Project: Cassandra
          Issue Type: Improvement
          Components: Core
            Reporter: T Jake Luciani
            Priority: Minor
             Fix For: 3.0

LCS has a number of minor issues (maybe major depending on your perspective).

LCS is primarily used for wide rows so for instance when you repair data in LCS you end up
with a copy of an entire repaired row in L0.  Over time if you repair you end up with multiple
copies of a row in L0 - L5.  This can make predicting disk usage confusing.  

Another issue is cleaning up tombstoned data.  If a tombstone lives in level 1 and data for
the cell lives in level 5 the data will not be reclaimed from disk until the tombstone reaches
level 5.

I propose we add a "major" compaction for LCS that forces consolidation of data to level 5
to address these.

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