Ease of use is a reason to support names, not to intentionally disallow raw IPs. Not using names is convenient if you want to erect a temporary cluster on a group of machines you don't own.
You have a user access, but name resolution is not always defined. As a user you cannot change /etc/hosts. On Jul 29, 2013 5:46 PM, "Chris Embree" <[email protected]> wrote: > 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? >> > >
