I didn't see the size of the cluster described, but watch out for having timestamps as your row keys, for you are going to have hot spots (all timestamps in one token range).
What is your replication factor and the size of the cluster?
This might be improved with vNodes, though I'm not sure how granular and automatic the subnodes are. If they are just an even range (e.g. 256 vnodes across the same 00-ff range), then you will have the same problem.
This is the major reason why Datastax pushes random ordered partitioning so much, it's easy to get into hot water with byte-ordered keys.
What is your replication factor and the size of the cluster?
This might be improved with vNodes, though I'm not sure how granular and automatic the subnodes are. If they are just an even range (e.g. 256 vnodes across the same 00-ff range), then you will have the same problem.
This is the major reason why Datastax pushes random ordered partitioning so much, it's easy to get into hot water with byte-ordered keys.