You have to use private IPs, but if an instance dies you have to bootstrap it with replace token flag. If you use EC2 I'd recommend Netflix's Priam tool. It manages all that stuff, plus you have S3 backup.


Andrey


On Mon, Feb 11, 2013 at 11:35 AM, Brian Tarbox <tarbox@cabotresearch.com> wrote:
How do I configure my cluster to run in EC2?  In my cassandra.yaml I have IP addresses under seed_provider, listen_address and rpc_address.

I tried setting up my cluster using just the EC2 private addresses but when one of my instances failed and I restarted it there was a new private address.  Suddenly my cluster thought it have five nodes rather than four.

Then I tried using Elastic IP addresses (permanent addresses) but it turns out you get charged for network traffic between elastic addresses even if they are within the cluster.

So...how do you configure the cluster when the IP addresses can change out from under you?

Thanks.

Brian Tarbox