cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Marcus Eriksson (JIRA)" <j...@apache.org>
Subject [jira] [Reopened] (CASSANDRA-7272) Add "Major" Compaction to LCS
Date Thu, 08 Jan 2015 09:05:36 GMT

     [ https://issues.apache.org/jira/browse/CASSANDRA-7272?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Marcus Eriksson reopened CASSANDRA-7272:
----------------------------------------
      Assignee: Marcus Eriksson

7019 is supposed to improve the tombstone compactions we do when there are no other compactions
to do - this ticket adds major compaction to LCS

> Add "Major" Compaction to LCS 
> ------------------------------
>
>                 Key: CASSANDRA-7272
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7272
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: T Jake Luciani
>            Assignee: Marcus Eriksson
>            Priority: Minor
>              Labels: compaction
>             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.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message