On Tue, Mar 31, 2009 at 8:08 AM, Jun Li <jltz922...@gmail.com> wrote:
....

> Compared to your configuration for 8 clients, I will need one more machine
> to repeat your experience. Do you have your own special settings (JVM Heap,
> Memory,  etc.) in HDFS or in HBase, that are different than the default
> settings? If you do have such settings, could you share them with me? You
> show "io.map.index.skip" in your email, do you recommend me to play with
> it?
>

I was using defaults.  Maybe my hardware is better than yours.  Tell us
about yours (RAM)?  I suggested io.map.index.skip because you were OOME'ing
and thats the thing that most directly effects memory use.

You have tasktrackers running on all these nodes?  Try running with less
than the default of two concurrent mappers.  See if that makes a
difference.  Does N=3 work?



> In my actual solution that I am planning to build upon HBase, I can manage
> to have many machines to form the HBase cluster, say, over a hundred of
> VMs.
> Based on your experience, what would be the performance impact of adding
> more and more region servers, to serve the concurrent clients, in the
> current implementation of HBase (version 0.19.0 or higher)?  I would image
> the number of concurrent clients that can be served should grow, up to
> certain point, and then gets saturated.
>

Yeah, generally, adding modes ups the amount of writes the cluster can
carry.

St.Ack

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