Ivan Pepeljnak’s makes an important point in his webinar on Cloud Computing Networking: as a customer, understand the QoS and SLA Guarantees that your public cloud provider offers. Whatever Tenant A does should not impact the performance of Tenant B. At a very minimum, there should be some guarantees on bandwidth, IO operations, and CPU cycles for every tenant. You don’t want to have the noisy neighbor who hogs up resources that leaves you no choice but to reboot your VM with the hope of getting reassigned to a physical server with less load. An AWS Small Instance is an example of an environment where you might encounter this scenario.