Modern world could not function properly without a large number of data centers. The reason can be found in the CDN technology. Content delivery or content distribution network nowadays helps to almost every user across the Global Net, everyday. Such system makes the content technologically closer to users to improve the quality of how their requests satisfying. End-user can feel it in a better performance, a faster page load time and a better response time. To make this happened, CDN data should be distributed in multiple data centers all over the globe.
Technological closeness consists of three components: available port on a way to user, speed of cables and the most important – geographical closeness. That means, that bigger amount of delivery servers for content data network improves its effectiveness. Popular content distribution companies hold very different number of PoPs (points of presence). For example, companies Amason ClowdFront, CDNsun and MaxCDN have 52 and 85 and 16 points of presence respectively. Every specific company decides where to place their data centers. ClowdFront focuses on North America (20 PoPs), while CDNsun has the largest number of points of presence in Europe (44 PoPs). However, some companies decide to pay the main attention not to number of PoPs, but to improve the quality of communications. Such companies sometimes have a small number of points of presence, but still competitive.
Data centers are usually located in the vicinity or within PoP (point of presence). They provide functions of processing, dissemination and storage of cloud data cdn. Data centers reduce total costs of IT-structure’s ownership by the effective use of technology. This can be achieved by the consolidation of computing resources and data storage resources. Data centers reduce administration costs for all structure and allow redistribution of loads. First data centers were made right after the birth of computer industry. But companies started calling them that way only when engineers began to use a hierarchical design for their building. Hierarchical design includes location of servers in separate rooms. The largest building of centers was in the last five years of the twentieth century. Design and construction of data centers is a well-studied area nowadays. Formed strict standards establish requirements for the design of centers. Typical structure of data center includes information infrastructure (server equipment), telecommunications infrastructure (interconnection between elements) and engineer infrastructure (conditioning and other). The interaction between servers and other network equipment requires work of network services. Data network services are provided by special processes of network operation system. Such services provide data storage, communication, presentation or manipulation. Different services can use peer-to-peer architecture (based on application layer network protocols) or client-server to realize their functions.