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Posted to dev@accumulo.apache.org by "Keith Turner (Created) (JIRA)" <ji...@apache.org> on 2011/10/28 21:13:32 UTC
[jira] [Created] (ACCUMULO-96) Need to handle case where tablet has
lots of delete entries
Need to handle case where tablet has lots of delete entries
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Key: ACCUMULO-96
URL: https://issues.apache.org/jira/browse/ACCUMULO-96
Project: Accumulo
Issue Type: Bug
Components: tserver
Reporter: Keith Turner
Assignee: Keith Turner
Currently Accumulo only drops delete entries when its major compacting all files. All files may never be compacted. Lots of delete entries building up can be problematic for scan performance.
Possible solutions :
* Keep a count of the # of delete entries per file. Compact all when the ratio of delete entries to entries crosses a threshold.
* When a scan encounters a tablet w/ a lot of delete entries, schedule a majc. This is reactive, but removes the need for bookkeeping in the previous solution.
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[jira] [Commented] (ACCUMULO-96) Need to handle case where tablet
has lots of delete entries
Posted by "Keith Turner (Commented) (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/ACCUMULO-96?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13138662#comment-13138662 ]
Keith Turner commented on ACCUMULO-96:
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A work around when the user has inserted a lot of deletes, is to force a compaction on the range of the table where the deletes were inserted.
> Need to handle case where tablet has lots of delete entries
> -----------------------------------------------------------
>
> Key: ACCUMULO-96
> URL: https://issues.apache.org/jira/browse/ACCUMULO-96
> Project: Accumulo
> Issue Type: Bug
> Components: tserver
> Reporter: Keith Turner
> Assignee: Keith Turner
>
> Currently Accumulo only drops delete entries when its major compacting all files. All files may never be compacted. Lots of delete entries building up can be problematic for scan performance.
> Possible solutions :
> * Keep a count of the # of delete entries per file. Compact all when the ratio of delete entries to entries crosses a threshold.
> * When a scan encounters a tablet w/ a lot of delete entries, schedule a majc. This is reactive, but removes the need for bookkeeping in the previous solution.
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