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Date: Thu, 28 Oct 2010 14:09:27 -0700
Message-ID: <AANLkTi=T0EBL-==Bwh7e7J2ULs0tDiLcgfeBZRv98EJ5@mail.gmail.com>
Subject: Re: Multi-Master Hadoop Configuration
From: Konstantin Shvachko <shv.hadoop@gmail.com>
To: common-dev@hadoop.apache.org
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Yes. Only one master, called name-node, is managing HDFS, and only one
master, called job tracker, is managing MapReduce cluster.
You can also read some online documentation, may be even publications.
Thanks,
--Konstantin

On Wed, Oct 27, 2010 at 3:28 PM, Wang, Chengwei <wangcw@gatech.edu> wrote:

> Thanks for pointing it out!
>
> Because it did not mentioned how may masters in the practice of 4000 nodes,
> is there only one master managing 4000 slaves?
>
> Thanks
> Chengwei
>
> ----- Original Message -----
> From: "Allen Wittenauer" <awittenauer@linkedin.com>
> To: "<common-dev@hadoop.apache.org>" <common-dev@hadoop.apache.org>
> Sent: Wednesday, October 27, 2010 6:08:10 PM
> Subject: Re: Multi-Master Hadoop Configuration
>
>
> On Oct 27, 2010, at 2:55 PM, Wang, Chengwei wrote:
>
> > Hi All,
> >
> > I've searched for a while on the possibility to configure multiple
> masters to govern large number of slaves, but I barely found any except for
> multi-masters for backup in HBase. Is one master enough to support thousands
> of slaves? Or in real we just configure separate Hadoop instances in a data
> center(I mean independent master-slaves sets on thousands of hosts)?
> >
> > I really appreciate that someone here could enlighten me on those
> questions!
>
> This is question #3 on the Hadoop FAQ.
>
> http://wiki.apache.org/hadoop/FAQ#How_well_does_Hadoop_scale.3F
>

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