Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Date: Tue, 28 Jul 2015 17:08:05 +0000 (UTC)
From: "Jonathan Ellis (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Message-ID: <JIRA.12709760.1398172235000.309019.1438103285664@Atlassian.JIRA>
In-Reply-To: <JIRA.12709760.1398172235000@Atlassian.JIRA>
References: <JIRA.12709760.1398172235000@Atlassian.JIRA>
 <JIRA.12709760.1398172235274@arcas>
Subject: [jira] [Commented] (CASSANDRA-7066) Simplify (and unify) cleanup of
 compaction leftovers
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-7066?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14644659#comment-14644659 ] 

Jonathan Ellis commented on CASSANDRA-7066:
-------------------------------------------

Granted, but a bug in the implementation could lead to similar results.  I'd be a lot more comfortable with a design whose failure scenario is "we do extra compaction" than "we silently lose data."

> Simplify (and unify) cleanup of compaction leftovers
> ----------------------------------------------------
>
>                 Key: CASSANDRA-7066
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7066
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Benedict
>            Assignee: Stefania
>            Priority: Minor
>              Labels: benedict-to-commit, compaction
>             Fix For: 3.0 alpha 1
>
>         Attachments: 7066.txt
>
>
> Currently we manage a list of in-progress compactions in a system table, which we use to cleanup incomplete compactions when we're done. The problem with this is that 1) it's a bit clunky (and leaves us in positions where we can unnecessarily cleanup completed files, or conversely not cleanup files that have been superceded); and 2) it's only used for a regular compaction - no other compaction types are guarded in the same way, so can result in duplication if we fail before deleting the replacements.
> I'd like to see each sstable store in its metadata its direct ancestors, and on startup we simply delete any sstables that occur in the union of all ancestor sets. This way as soon as we finish writing we're capable of cleaning up any leftovers, so we never get duplication. It's also much easier to reason about.


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