Amazon Cloud Goes Single-Tenant With Dedicated Instances
The addition of Dedicated Instances to VPC lets cloud users run instances on dedicated hardware, meaning their cloud is isolated from others. Dedicated Instances ensure that no other companies are running on the same physical host, Jeff Barr, AWS evangelist, wrote in a blog post unveiling Dedicated Instances.
Dedicated Instances, which make cloud computing single-tenant, are designed for cloud customers that have regulatory and security requirements that prohibit their data from being physically stored on shared hardware. Instead of being stored on virtual machines on the same server, Dedicated Instances store data on physically isolated hardware, Amazon said.
Previously, each VPC and each Amazon EC3 instance running in a VPC had been assigned a tenancy attribute, which, when set to default, enables a single physical machine to run instances launched by different Amazon cloud users.
"Setting the tenancy of a VPC to 'dedicated' when the VPC is created will ensure that all instances launched in the VPC will run on single-tenant hardware," Barr wrote. "The tenancy of a VPC cannot be changed after it has been created."
Barr wrote that users can also launched Dedicated Instances in a non-dedicated VPC by setting the instance tenancy to "dedicated" when users call RunInstances.
Dedicated Instances are supported for all EC2 instances types, with the exception of Micro, Cluster Compute and Cluster GPU, Barr wrote.
And while Dedicated Instances guarantee that data is on physically isolated hardware, it does not guarantee that all instances will be saved on the same piece of single-tenant hardware, Barr cautioned.
"It is important to note that launching a set of instances with dedicated tenancy does not in any way guarantee that they'll share the same hardware (they might, but you have no control over it)," he wrote. "We actually go to some trouble to spread them out across several machines in order to minimize the effects of a hardware failure."
Amazon will add a $10-per-hour charge when users have at least one Dedicate Instance running in a region. For users running hundreds or thousands of instances pre region, the cost can approach $0 per instance. Amazon also added a premium to per-hour pricing for the specific instances used as dedicated machines. Barr wrote that the fee is to off-set potential revenue losses from Dedicate Instances creating unused capacity.
"When you launch a Dedicated Instance, we can't use the remaining slots on the hardware to run instances for other AWS users," Barr wrote. "Therefore, we incur an opportunity cost when you launch a single Dedicated Instance. Put another way, if you run one Dedicated Instance on a machine that can support 10 instances, 9/10ths of the potential revenue from that machine is lost to us."
The launch of Dedicated Instances comes as Amazon Web Services continues to beef up the capabilities of it VPC plays. Earlier this month, AWS updated its Virtual Private Cloud play with a set of free networking tools that enable companies to build a virtual network and specify which resources they wish to make directly accessible to the Internet and which they do not.