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Date: Wed, 23 Jun 2010 20:32:10 +0800
Message-ID: <AANLkTik7VDpYOqDo8z871Bd2satgMLcre2qVJFhLSJWx@mail.gmail.com>
Subject: Why data read performs better than data write in HBase?
From: =?GB2312?B?yrfTor3c?= <shiyingjie1983@gmail.com>
To: dev@hbase.apache.org
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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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