gistfile1.txt

QoS for clouds

* The universal scalability law applies to you, too.
* The x value shifts to the left, when you have a failure (less capacity)
* the y value shifts up when you have a failure (recovery is effectively a client workload)
* Thus, you need to be below the point of contention to avoid service degradation upon failure.
* To capacity plan for adversarial workloads, provided throughput/iops needs to be a function
  tied to the amount of provisioned storage.
* Total throughput per unit of storage should be derived from a value far enough below the point
  of contention to compensate for failures.