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Re: Why Hadoop force using DNS?
Chris Embree 2013-07-29, 14:45
Just for clarity,  DNS as a service is NOT Required.  Name resolution is.
 I use /etc/hosts files to identify all nodes in my clusters.

One of the reasons for using Names over IP's is ease of use.  I would much
rather use a hostname in my XML to identify NN, JT, etc. vs. some random
string of numbers.
On Mon, Jul 29, 2013 at 10:40 AM, Greg Bledsoe <[EMAIL PROTECTED]> wrote:

> I can third this concern.  What purpose does this complexity increasing
> requirement serve?  Why not remove it?
>
> Greg Bledsoe
>
> From: 武泽胜 <[EMAIL PROTECTED]>
> Reply-To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> Date: Mon, 29 Jul 2013 08:21:51 -0500
> To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> Subject: Re: Why Hadoop force using DNS?
>
> I have the same confusion, anyone who can reply to this will be very
> appreciated.
>
> From: Elazar Leibovich <[EMAIL PROTECTED]>
> Reply-To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
> Date: Thursday, July 25, 2013 3:51 AM
> To: user <[EMAIL PROTECTED]>
> Subject: Why Hadoop force using DNS?
>
> Looking at Hadoop source you can see that Hadoop relies on the fact each
> node has resolvable name.
>
> For example, Hadoop 2 namenode reverse look the up of each node that
> connects to it. Also, there's no way way to tell a database to advertise an
> UP as it's address. Setting datanode.network.interface to, say, eth1, would
> cause Hadoop to reverse lookup UPs on eth1 and advertise the result.
>
> Why is that? Using plain IPs is simple to set up, and I can't see a reason
> not to support them?
>