Re: Cluster sizing guidelines
The i2.8xlarge and hs1.8xlarge EC2 instance types would provide opportunity for testing what really happens today when you attempt a high density storage architecture with HDFS and HBase. The hs1 type has 24 spinning disks. I think the i2.8xlarge better represents near-future challenges in effective utilization: it has 8 x 800 GB SSD and 244 GB of RAM. Would be hard to get ahold of and very expensive to operate though.