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Date: Thu, 07 Feb 2008 21:05:36 -0800
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To: hbase-user@hadoop.apache.org
Subject: Re: HBase Random Read Performance
References: <47ABCC44.20208@openplaces.com>
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Tthe test described can only favor mysql (single column, just a million 
rows).  Do you need Hbase? 

You might also tell us more about your hbase setup.  Is it using localfs 
or hdfs?  Is it a distributed hdfs or all on single server?

Thanks,
St.Ack


Joost Ouwerkerk wrote:
> I'm working on a web application with primarily read-oriented 
> performance requirements.  I've been running some benchmarking tests 
> that include our application layer, to get a sense of what is possible 
> with Hbase.  A variation on the Bigtable test that is reproduced by 
> org.apache.hadoop.hbase.PerformanceEvaluation, I'm randomly reading 1 
> column from a table with 1 million rows.  In our case, the contents of 
> that column need to be deserialized by our application (which adds 
> some overhead that I'm also trying to measure), the deserialized 
> contents represent a little over 1K of data.
> Although a single thread can only achieve 125 reads per second, with 
> 12 client threads (from 3 different machines) I'm able to read as many 
> as 500 objects per second.  Now, I've replicated my test on a basic 
> MySQL table and am able to get a throughput of 2,300 reads/sec; 
> roughly 5 times what I'm seeing with Hbase.  Besides the obvious code 
> maturity thing, is the discrepancy related to random reads not 
> actually being served from memcache, but rather from the disk, by 
> Hbase?  The HBase performance page 
> (http://wiki.apache.org/hadoop/Hbase/PerformanceEvaluation) shows 
> random reads(mem) as "Not implemented."
>
> Can anyone shed some light on the state of HBase's memcaching?
> Cheers,
> Joost.