Cloud computing infrastructure

Cloud computing requires more than just a server room, and the different providers employ different technologies. In all cases, cloud computing relies on data centers in multiple geographic locations, with multiple redundancies of everything. It's quite a challenge to locate an area that is geologically stable and relatively free from severe weather events or other natural disasters, making redundancies of locations, in addition to redundancies of utilities, a necessity.

Cloud data centers have moved away from the "racks-in-a-room" or "raised floor" design of traditional data centers. One of the more common designs for cloud data centers is to modify a shipping container to hold racks of servers, and then linking multiple containers together into a large center. The container-based design is used more for stability, space efficiency, and physical isolation of machines. A forty-foot tall rack of servers would be highly unstable and extremely difficult to manage. But a stack of four containers is very stable, and each container is as easy to manage as a small server room. It's also more efficient to cool a number of small rooms as compared to a giant warehouse.

For Azure, Microsoft has taken the container concept a little farther. Microsoft's Azure containers (called Generation 4 Modular Data Centers or G4MDC) are not based on a shipping container, although the end design resembles one. Technically, Microsoft's containers are classified as air handling units and the servers as heaters. Cooling is achieved by pulling outside air through filters, into the container, and around the servers at high velocity. In fact, some of Microsoft's new data centers won't even have roofs! Each G4MDC unit is completely self-contained with airflow regulation, and its own connections for power and bandwidth. Each 40-foot unit can accommodate up to 2,000 servers, and some of Microsoft's facilities will house 400,000 to 500,000 servers.