amazon web services - Cassandra Ec2MultiRegionSnitch or GossipingPropertyFileSnitch for AWS regions -

we have 3 cassandra nodes in u.s. aws region , 3 nodes in singapore aws region. if have build multi-data center mandatory use ec2multiregionsnitch? or can use gossipingpropertyfilesnitch?

and should use private ip addresses both broadcast addresses , listen address here?

as system administrator told me, don't need public ip these , private ip should work both can communicate each other. doubtful of that. can kindly shed light on this?

there's no reason not use ec2multiregionsnitch snitching method, if intend use networktopologystrategy keyspace (which makes cassandra datacenter aware). otherwise, have configure topology manually, below:

in ec2 deployments, region name treated data center name , availability zones treated racks within data center. example, if node in us-east-1 region, us-east data center name , 1 rack location.

so, using it, cassandra automatically information instances' metadata.

as public ips, need them, because can't establish peering between vpcs across regions, instances can't communicate each other inside vpcs.

again, datastax's documention says how that:

in cassandra.yaml, set listen_address private ip address of node, , broadcast_address public ip address of node.