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https://issues.apache.org/jira/browse/CASSANDRA-4237?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Yuki Morishita updated CASSANDRA-4237:
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    Attachment:     (was: 4237.txt)
    
> 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
>
>
> 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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