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https://issues.apache.org/jira/browse/CASSANDRA-4237?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13449984#comment-13449984
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Jonathan Ellis commented on CASSANDRA-4237:
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Hmm, I think this means that if perform a scheduled forceFlush but it's clean,
we don't schedule another flush attempt.
Maybe brute force every 10s isn't so bad? Bonus: accomodates changing the
period via mbean for free (which we should allow), without having to try to
retrieve a ScheduledTask and cancel it.
> Add back 0.8-style memtable_lifetime feature
> --------------------------------------------
>
> Key: CASSANDRA-4237
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4237
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Affects Versions: 1.0.0
> Reporter: Jonathan Ellis
> Assignee: Yuki Morishita
> Priority: Minor
> Fix For: 1.2.0
>
> Attachments: 4237.txt
>
>
> Back in 0.8 we had a memtable_lifetime_in_minutes setting. We got rid of it
> in 1.0 when we added CASSANDRA-2427, which is a better way to ensure
> flushing on low-activity memtables.
> However, at the same time we also added the ability to disable durable
> writes. So it's entirely possible to configure a low-activity memtable, that
> isn't part of the commitlog. So, we should add back a memtable lifetime
> setting.
> An additional motive is pointed out by
> http://www.fsl.cs.sunysb.edu/~pshetty/socc11-gtssl.pdf: if you have a *high*
> activity columnfamily, and don't require absolute durability, the commitlog
> is redundant if you are flushing faster than the commitlog sync period. So,
> disabling durable writes but setting memtable lifetime to the same as the
> commitlog sync would be a reasonable optimization.
> Thus, when we add back memtable lifetime, I think we should measure it in
> seconds or possibly even milliseconds (to match commitlog_sync_period) rather
> than minutes.
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