Content replica placement method and content replica placement system used in content delivery network (CDN)

Abstract

The invention discloses a content replica placement method and a content replica placement system used in a content delivery network (CDN). According to the content replica placement method, a chosen replica placement node needs to meet the service response time requirement primarily. For any node Mi in the CDN, when the node Mi serves as an access node, preparatory replica placement node sets Ci which enable the node Mi to meet the service response time requirement and the local-storage requirement are found. A preparatory node Ns which has highest frequency of occurrence in the preparatory replica placement node sets is found from all the preparatory replica placement node sets. For each preparatory replica placement node set Ci which comprises the preparatory node Ns, the total number of requests of a corresponding access node Mi is calculated, and if the number is smaller than the maximum load request number of the preparatory node Ns, the node is chosen as an actual replica placement node, and otherwise a node which has second highest frequency of occurrence is considered. According to the content replica placement method, upper limit of load of each node of the CDN is limited based on that the node meets the servicing response time requirement, and simultaneously content replica placement quantity is reduced, and expense is optimized and updated.

Description

technical field [0001] The invention relates to the technical field of content distribution network, in particular to a method and system for placing content copies in a CDN network. Background technique [0002] Content Delivery Network (CDN) is widely used to solve the situation of Internet network congestion and improve the response speed of users visiting websites. Selecting which nodes in the CDN to place content copies is a key issue in the CDN. The current research hotspot is the copy placement problem that meets the service response time requirements, that is, the CDN nodes must meet the requested service response time requirements while providing services. How to place the copy in this case is a question. [0003] The existing method is to select some nodes in the CDN as content copy placement nodes. The principle of selection is to consider the overall cost of the system to be the smallest. However, this selection method has the following three problems: First, th...

AI Technical Summary

Problems solved by technology

[0003] The existing method is to select some nodes in the CDN as content copy placement nodes. The principle of selection is to consider the overall cost of the system to be the smallest. However, this selection method has the following three problems: First, this type of method is difficult to select. When copying nodes, the cost of storing copies in the system and the cost of updating copies are considered. Therefore, when the content that needs to be created in the CDN increases, and a single node cannot store copies or the size and type of stored files are limited, these algorithms do not give a solution. Program

Second, this type of method assumes that the service capabilities of each node are not limited. If a node is close to all other nodes, it may happen that only this node is required as a replica node to meet the service response time requirements of all nodes. Since all requests are concentrated on this node, it may cause the node's response delay or non-response

Third, this type of method does not take into account that different business types have different requirements for service response time

Therefore, the existing CDN network cannot meet the actual business needs when selecting a copy storage node, so a copy placement method that can overcome the above shortcomings is needed

Images