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From "Yang Yang (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-2735) Timestamp Based Compaction Strategy
Date Fri, 17 Jun 2011 22:06:47 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-2735?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13051350#comment-13051350
] 

Yang Yang commented on CASSANDRA-2735:
--------------------------------------

true, I don't really care about expired data, I'm happy as long as we have an expiring counter
that "mostly" works or works with certain cautions.

but it seems that the "changing order" can come not only from compaction (which is fixed for
realistic scenarios here),
but also from effects of message drops.

"compact( compact (Add1, delete), Add2) " is the same as receiving Add1, delete , Add2 in
messages.

but we know that messages can be easily dropped. 
so let's say the delete is dropped, then we replay it later (through repair for example),
the same issue appears. 
I think the latter issue can be fixed by changing the TTL reconcile rule so that reconciled
death time is the older death time, not timestamp+new_TTL.

anyhow I think we users of the counters api need to understand that placing a delete shortly
after your last update, or place an update shortly after delete is most likely not going to
work.  this patch fixes half of the issue, but it still remains. 

> Timestamp Based Compaction Strategy
> -----------------------------------
>
>                 Key: CASSANDRA-2735
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-2735
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Core
>            Reporter: Alan Liang
>            Assignee: Alan Liang
>            Priority: Minor
>              Labels: compaction
>         Attachments: 0004-timestamp-bucketed-compaction-strategy.patch
>
>
> Compaction strategy implementation based on max timestamp ordering of the sstables while
satisfying max sstable size, min and max compaction thresholds. It also handles expiration
of sstables based on a timestamp.

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