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From: Mohammad Tariq <dontariq@gmail.com>
Date: Fri, 7 Dec 2012 12:27:51 +0530
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Subject: Re: Multiple regionservers on a single node
To: "user@hbase.apache.org" <user@hbase.apache.org>
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Hello all,

     I would like to add 2 cents from my side. Even if we have superior
CPU, RAM and Disk, the IO still remains the bottleneck. The CPU would never
have much impact on the overall performance, no matter how powerful it is,
if there is no considerable evolution of IO. Also, if we have multiple RSs,
our DN and TT may face memory issues. What do you guys say?

Thank you.

Regards,
    Mohammad Tariq


On Fri, Dec 7, 2012 at 9:32 AM, Robert Dyer <rdyer@iastate.edu> wrote:

> I too am interested in running multiple RS on a single node.
>
> I have a very small cluster where all nodes are identical.  However, I was
> just given a very powerful node to add into this cluster which effectively
> doubles the total CPUs, RAM, and HDDs in the cluster.
>
> As such, when I run a MR job half the jobs go to this single, new node yet
> most of the data is not local due to HBase balancing the regions.
>
> Does it make sense for me to run multi-RS on this node?
>
>
> On Mon, Dec 3, 2012 at 3:39 PM, Ishan Chhabra <ichhabra@rocketfuel.com
> >wrote:
>
> > Hi,
> > Has anybody tried to run multiple RegionServers on a single physical
> > node? Are there deep technical issues or minor impediments that would
> > hinder this?
> >
> > We are trying to do this because we are facing a lot of GC pauses on the
> > large heap sizes (~70G) that we are using, which leads to a lot of
> timeouts
> > in our latency critical application. More processes with smaller heaps
> > would help in mitigating this issue.
> >
> > Any experience or thoughts on this would help.
> > Thanks!
> >
> > --
> > *Ishan Chhabra *| Rocket Scientist | Rocketfuel Inc. | *m *650 556 6803
> >
>
>
>
> --
>
> Robert Dyer
> rdyer@iastate.edu
>

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