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From "Ryan Rawson" <ryano...@gmail.com>
Subject Re: Review Request: HBASE-2997 performance improvements
Date Wed, 15 Sep 2010 22:25:51 GMT

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This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/843/#review1230
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src/main/java/org/apache/hadoop/hbase/KeyValue.java
<http://review.cloudera.org/r/843/#comment4189>

    key values are only used by 1 thread at a time, so no.
    
    and even if they were shared, we'd just result in the current situation - use more cpu
than is theoretically necessary.



src/main/java/org/apache/hadoop/hbase/KeyValue.java
<http://review.cloudera.org/r/843/#comment4190>

    it actually is worth it... also key values tend to be short lived, but recopying this
array out half a dozen times during a scan is pricy according to the profiler.  6% cpu.



src/main/java/org/apache/hadoop/hbase/KeyValue.java
<http://review.cloudera.org/r/843/#comment4191>

    in a 64 bit jvm you cannot read a partial long, the updates are atomic.
    
    this is part of the spec.  also single threaded comment above.


- Ryan


On 2010-09-14 15:41:01, Ryan Rawson wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/843/
> -----------------------------------------------------------
> 
> (Updated 2010-09-14 15:41:01)
> 
> 
> Review request for hbase.
> 
> 
> Summary
> -------
> 
> HBASE-2997 performance improvements
> 
> 
> This addresses bug HBASE-2997.
>     http://issues.apache.org/jira/browse/HBASE-2997
> 
> 
> Diffs
> -----
> 
>   src/main/java/org/apache/hadoop/hbase/KeyValue.java abd5a6b 
> 
> Diff: http://review.cloudera.org/r/843/diff
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> Ryan
> 
>


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