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https://issues.apache.org/jira/browse/HBASE-3588?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13001329#comment-13001329
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ryan rawson commented on HBASE-3588:
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interesting idea, this needs to fit in the context of the acid work stack is
doing. In the discussion of that issue, it turned out that we were required to
always read from the most recent read point between each row.
How much time is this saving? It was expected that a memstore insertion would
be REALLY fast. Now with the MemstoreLAB stuff, that might not be so true
anymore...
> Proposal to optimize ReadWriteConsistencyControl
> ------------------------------------------------
>
> Key: HBASE-3588
> URL: https://issues.apache.org/jira/browse/HBASE-3588
> Project: HBase
> Issue Type: Improvement
> Components: regionserver
> Reporter: dhruba borthakur
> Assignee: dhruba borthakur
> Attachments: rwcc.trunk.1, rwcc.trunk.1
>
>
> The ReadWriteConsistencyControl (RWCC) mechanism facilitates making a set of
> memstore updates atomically visible to readers. Also, the
> rwcc.completeMemstoreInsert() blocks till the memstore read point advances to
> the current writeNumber. This is done to ensure that if an application that
> does a put immediately issues a new get call for the same key, then the get
> should see the values inserted by the previous call to put. The current
> implementation assumes this worst-case and penalizes the put rpc to not
> return to the client until the read point advances to this transaction's
> write number.
> In many use-cases, the application never actually issues a get for the most
> recent put that it inserted. In this case, it would be nice if we can
> transfer the penalty (of blocking) to the get call that follows the initial
> put.
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