The document describes Rackspace's Analytical Compute Grid (ACG), an elastic "big data" infrastructure built on Rackspace Private Cloud powered by OpenStack. The ACG allows hosting of ever-growing data sets, rapid scalability, and ease of maintenance. It utilizes a variety of storage types and leverages open source technology. The architecture includes hypervisor servers, databases, and an indexing structure that distributes data across instances and enables parallelized queries of large data sets.