Hi, We are currently wondering about the best way to configure network architecture to have a Cassandra cluster multi DC.
Reading previous messages on this mailing list, I see 2 main ways to do this: 1 - 2 private VPC, joined by a VPN tunnel linking 2 regions. C* using EC2Snitch (or PropertyFileSnitch) and private IPs. 2 - 2 public VPC. C* using EC2MultiRegionSnitch (and so public IPs for seeds and broadcast, private for listen address). On solution one we are not confident on VPN tunnel about stability and performances, the rest should work just fine. On solution 2, we would need to open IPs one by one on 3 ports (7000, 9042, 9160) at least. 100 entries in a security group would allow us to have a maximum of ~30 nodes. An other issuer is that a ring describe (using astyanax let's say) would also give to clients public IPs, our clients which are also inside the VPC, would have to go to the internet before coming back to VPC, creating unnecessary latencies. What are your advices regarding best practices for a multiDC (cross region) inside AWS cloud ? And by the way, how to configure Astyanax when using EC2MultiRegionSnitch (and public IP for broadcasting) to use private IPs instead of public ones ? Alain
