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From Jean-Daniel Cryans <jdcry...@apache.org>
Subject Re: Why data read performs better than data write in HBase?
Date Wed, 23 Jun 2010 16:44:50 GMT
When I run PE, random/seqRead are always much slower than
random/seqWrite so it seems to be something about your env or you are
confused by the output of that test.

What are the numbers you see?


On Wed, Jun 23, 2010 at 5:32 AM, 史英杰 <shiyingjie1983@gmail.com> wrote:
> Hi, All
>    Recently I did some tests on HBase, using the performance eveluation
> package  in HBase 0.20.3. There are some situations I can't understand. I
> found that read perform better than write, no matter sequential read or
> random read during the test. But in BigTable's paper, writes perform better
> than reads, because each tablet server appends all incoming writes to a
> single commit log and uses group commit to stream these writes efficiently
> to GFS. In HBase, we set the autoFlush=false, and the flush size is 64M, so
> writes should perform better than reads, but the result is just the
> opposite. Please help me to explain this phenomenon, thanks a lot!
> Yingjie

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