Analysis of the method of optimized data caching in the Content Delivery Network

Concept of Content Delivery Network (CDN) system and methods of caching data on edge servers were considered in this paper. The main task of the CDN network is providing the qualitative information delivery to the end user. Content Delivery Network is a geographically distributed network, that contain a number of content servers and routers. As a rule, it consists of a main node (Origin), and caching nodes (Edges) – points of presence, which can be located in various parts of the world. All content is stored and updated on the Origin server. The structural scheme of organizing the work of the CDN network, consisting of three complementary planes, was presented. Each plane performs special functions and has its own implementation features. Access Plane provides end-user access to content and the interaction of caching servers among themselves and on other planes. The load balancing plane is organized according to the principle of the DNS service and allows to redirect the user's requests to the nearest caching servers. This plane also inter-acts with the metric plane, which contains up-to-date information of the status of all servers involved in delivery and caching of data. As part of this paper, we proposed a method for optimized caching of data in the CDN network. The algorithm of this method is presented. Dependencies that make it possible to evaluate the work of this method in comparison with existing methods are given. The proposed method allows to significantly improve the Hit Ratio, and thus ensure efficient use of cached data and reduce the load on servers of origin.