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From: Sasha Dolgy <sdolgy@gmail.com>
Date: Wed, 27 Apr 2011 15:26:29 +0200
Message-ID: <BANLkTinkxCh_n_UjVriXS3zFE-n67=7btw@mail.gmail.com>
Subject: Re: advice for EC2 deployment
To: user@cassandra.apache.org
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if you migrate the instance, does Route53 automatically re-map all the
information to the new ec2 instance?  another issue is that cassandra
only maintains the IP of the other nodes, and not the hostname
(assumed based on output of the nodetool ring)  ...

which means, if you migrate the instance and Route53 does do some
auto-magic .. the private ip for the instance will have changed and
you will need to migrate that node back into the ring, while moving
the old referenced IP out ... we've had quite a lot of pain with this
in the past.  rule of thumb, if you want to upgrade / migrate an
instance, you need to remove it from the ring, do your work, bootstrap
it back to the ring .. i think this could be avoided if cassandra
maintained hostname references and not just IP references for nodes.

-sasha

On Wed, Apr 27, 2011 at 2:56 PM, William Oberman
<oberman@civicscience.com> wrote:
> While I haven't configured it for multi-region yet, Sasha is exactly righ=
t
> now how amzon's DNS works (returning private vs. public IP depending on i=
f
> the machine is local to the region or not).=A0 For extra fun, now that Ro=
ute53
> exists you can (somewhat trivially) map and dynamically maintain all EC2
> instances to stable DNS names (but make sure to use CNAMEs to get the DNS
> magic!).=A0 E.g.
> cassandra1.somethinghardtoguess.ec2.yourdomain.com ->
> weird.ec2.public.dns.name
>
> I'd drop in the somethinghardtoguess myself given Route53 can expose your
> internal network topology if someone can guess the DNS name.
>
> will