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 <ober...@civicscience.com> wrote: > While I haven't configured it for multi-region yet, Sasha is exactly right > now how amzon's DNS works (returning private vs. public IP depending on if > the machine is local to the region or not). For extra fun, now that Route53 > 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!). 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
