Can you talk a little bit about how many nodes it takes to maintain that write rate? We have our own system that's currently handling around 1% of that on a single node, with decent headroom but I've been looking for ways to distribute it. Certainly word on the street is that OpenTSDB performance is not good, at least relative to the resources you throw at it; however since it's based on HBase you can keep scaling even if it's expensive.