The network architecture of the content delivery network (CDN) and methods of the load balancing were examined in this paper. We have described the algorithm of end users’ request routing which allows selecting the optimum edge server to receive a content with maximum quality. The use of network system monitoring was offered. This system allows to efficiently assess the status of the network and promptly report possible problems. It was defined which parameters are needed to be monitored.
Graphic dependencies of CDN networks efficiency, hit ratio and response time depending on resizing cache were presented as result of the simulation. The dependencies demonstrate an important feature which means that increasing of the cache size doesn’t allow an effective use of CDNs. However, server response time to end users’ requests depends on a size of the cache. It was established that the use of CDN gives an opportunity to significantly save bandwidth, reduce server response time and in that way to provide services with a satisfactory quality and optimal use of network resources.
1. Awduche D., Chiu A., Elwalid A., Widjaja I. Overview and principles of internet traffic engineering. IETF, RFC3272, 2002. 2. Sivasubramanian S., Szymaniak M., Pierre G., “Replication for web hosting systems”, ACM Computing Surveys, vol. 36, no. 3, no. 3, pp. 291–334, 2004. 3. M. Kyryk, N. Pleskanka, M. Pitsyk, “QoS Mechanism in Content Delivery Network” Proceedings of the XIIIth International Conference TCSET’2016 Modern problems of radio engineering, telecommunications, and computer science of Lviv Polytechnic National University TCSET’2016. February 23 — 26, 2016 Lviv- Slavske, Ukraine. Publishing House of Lviv Polytechnic. — Р. 658–660. 4. Kyryk M., Pleskanka N. Reseached impact of parameters of the Н264 videocodec on quality of video signal Academic Journals of L’viv Polytechnic National University, Series of Radio Electronics and Telecommunication“, 2011. — No. 705. — pp. 161–166. 5. Mykhailo Klymash, Maryan Kyryk, Nazar Pleskanka, Volodymyr Yanyshyn Data Buffering Multilevel Model at a Multiservice Traffic Service Node // Smart Computing Review. Korea — Vol. 4. No. 4. August 31, 2014, p. 294-306. 6. Kyryk M., Pleskanka N., Pleskanka M. Content Delivery Network Usage Monitoring // Proceedings of 14th International IEEE conference “The experience of designing and application of CAD systems in microelectronics”, CADSM’2017, 21–25 February 2017, Poljana-Svalyava(Zakarpattya), Ukraine. — Lviv: Lviv Polytechnic Publishing House.P. 306–308. 7. Alzoubi, H. A., Rabinovich, M., and Spatscheck, O. MyXDNS: a resquest routing DNS server with decoupled server selection. In Proceedings of the 16th international conference on World Wide Web. May 2007, pp. 351 — 360. 8. Amini, L., Shaikh, A., and Schulzrinne, H. Effective peering for multi- provider content delivery services. In Proc. of 23rd Annual IEEE Conference on Computer Communications (INFOCOM’04), pp. 850–861, 2004. 9. Verma, D.C., Calo, S., and Amiri, K. Policy- based management of content distribution networks, IEEE Network, 16(2), pp. 34–39, 2002.10. Konstantinos Stamos, George Pallis, Athena Vakali, Dimitrios Katsaros, Antonis Sidiropoulos, Yannis Manolopoulos, CDNsim: A Simulation Tool for Content Distribution Networks, ACM Transactions on Modeling and Computer Simulation, Vol. 20, No. 2, Article 10, Publication date: April 2010. 11. Biliris A., Cranor C., Douglis F., Rabinovich M., Sibal S., Spatscheck O., and Sturm W. CDN brokering. Computer Communications, 25(4), pp. 393–402, 2002. 12. Buyya, R., Pathan, M., Broberg, J., and Tari, Z. A case for peering of content delivery networks, IEEE Distributed Systems Online, 7(10), 2006. 13. Cardellini, V., Colajanni, M., and Yu, P. S. Efficient state estimators for load control policies in scalable Web server clusters. In Proc. of the 22nd Annual International Computer Software and Applications Conference, 1998. 14. Cardellini V., Colajanni M., and Yu. P. S. Request redirection algorithms for distributed Web systems. IEEE Trans. on Parallel and Distributed Systems, 14(4), 2003.