yes, sure. Taking data from the same zone will reduce latency and save you some money.

On Wed, Feb 12, 2014 at 10:13 AM, Brian Tarbox <> wrote:
We're running a C* cluster with 6 servers spread across the four us-east1 zones.

We also spread our clients (hundreds of them) across the four zones.

Currently we give our clients a connection string listing all six servers and let C* do its thing.

This is all working just fine...and we're paying a fair bit in AWS transfer costs.  There is a suspicion that this transfer cost is driven by us passing data around between our C* servers and clients.

Would there be any value to trying to get a client to talk to one of the C* servers in its own zone?

I understand (at least partially!) about coordinator nodes and replication and know that no matter which server is the coordinator for an operation replication may cause bits to get transferred to/from servers in other zones.  Having said there a chance that trying to encourage a client to initially contact a server in its own zone would help?

Thank you,

Brian Tarbox