The expectation of a global presence of services leads to the need for large numbers of service instances allocated in a multitude of regional data centers in order to provide sufficient service capacity close to where the demand occurs. Scale of service instances is anticipated growing \gg 10⁴ raising new challenges for control and management. Pragmatically, it must become much easier to deploy service instances in data center, allocating resources, sharing them, installing and configuring data and software needed for service instances and integrating them into a singular service that appears to a consumer. Adjusting numbers and locations of service instances is seen as a basic control mechanism in order to follow regional or temporal fluctuations in demands.

The paper proposes a new concept of virtualizing whole data center environments and quickly deploying massive amounts of service instances. A virtualization layer takes care of resource allocation from different data center locations and all specifics when service instances are allocated in a particular data center. Virtualized data centers provide a consistent operating environment spanning multiple physical data center locations for the whole family of service instances. And vice versa, physical data centers host several execution environments for different services.

After a brief discussion of challenges coming with the scale of service instances we anticipate, the paper overviews virtual data centers and discusses one aspect in more detail how massive amounts of service instances can be deployed using a recursive approach.