Thanks Jabbar and Aaron.

Aaron - for broadcast_address , looks it is only working with EC2MultiRegionSnitch. but in our case, we will have one center in colo, and one center in ec2(sorry, did not make that clear, we'd like to replicate data from colo to EC2)

So can we still use broadcast_address? or other solutions? Is that easy to write a new Snitch for this?



On Thu, May 2, 2013 at 2:31 PM, aaron morton <> wrote:
Look at the broadcast_address in the yaml file
Aaron Morton
Freelance Cassandra Consultant
New Zealand


On 3/05/2013, at 9:10 AM, Jabbar Azam <> wrote:

I'm not sure why you want to use public Ip's in the other data centre. You're cassandra nodes in the other datacentre will be accessible from the internet

Personally I would use private IP addresses in the second data centre, on a different IP subnet.

A VPN is your only solution if you want to keep your data private and unhackable, as it's tunneling it's way through the internet

A slow network connection will mean your data is not in sync in both datacentres unless you explicitly specify quorum as your consisteny level in your mutation requests but your database throughput will be affected by this.

You bandwidth to the second datacentre and the quantity of your mutation requests will dictate how long it will take the second datacentre to get in sync with the primary datacentre.

I've probably missed something but there are plenty of intelligent people in this mailing list to fill the blanks :)


Jabbar Azam

On 2 May 2013 20:28, Daning Wang <> wrote:
Hi all,

We are deploying Cassandra on two data centers. there is slower network connection between data centers. 

Looks casandra should use internal ip to communicate with nodes in the same data center, and public ip to talk to nodes in other data center. We know VPN is a solution, but want to know if there is other idea.

Thanks in advance,