Design – Build – Run: Applied Practices and Principles for Production-Ready Software Development

5.4. The Primary and Secondary Data Centers

A data center is a highly fault-tolerant facility where an organization houses all its servers, networking components, and infrastructure. It has redundant power supplies and power sources, as well as redundant communications equipment. The facility uses air conditioning to keep the equipment at an optimum temperature. Data centers are totally secure and have strict security policies regarding anyone entering. Under normal circumstances, only operations staff is permitted entry. In addition, as you might expect, data centers contain special fire and emergency control equipment.

Data centers are critical to the organization. Because mission-critical systems are used to run the business, assist in the decision-making process, and form the basis of growth and revenue generation, a failure in the data center could be disastrous. Therefore, most organizations have two data centers — a primary data center (PDC) and a secondary data center (SDC), which in some cases is also referred to as the disaster recovery (DR) site or the alternative site.

Data centers can be of any size — a single room, multiple rooms, a floor, multiple floors, or an entire building. They are very carefully designed and constructed, with detailed standards, guidelines, and regulations. The floor is often raised to allow for better air flow and room for cabling. A raised floor can also alleviate interference caused by ground movement, and it's typically covered with specially ...