The CDN node cache adopts a three-level architecture of memory, solid-state hard disk, and hard disk. Through an independently developed intelligent cache migration algorithm, files can be dynamically migrated based on the popularity of files accessed by end users, always reserving valuable memory space for a large number of users. “Useful” video content to obtain high-performance output. After applying CDN, DNS returns not only IP addresses, but also CNAME, pointing to the global load balancing of CDN. Let’s take a look at the indicators that measure CDN service quality?
1. Hit rate
The resource accessed by the user happens to be in the cache system and can be returned directly to the user. The ratio of hits to visits indicates that the hit rate of commercial CDNs has now exceeded the current standard level, which is equivalent to amplifying the service capacity of the source site. Since no IP address is returned, the local DNS will send a request to the load balancing system again, and then enter the CDN global load balancing system for intelligent scheduling. View the IP address of the user, check the table to obtain the geographical location, find a relatively close edge node, check the location of the operator network user, find the edge node of the same network, check the load of the edge node, and find the node with a lighter load.
2. Return rate
The ratio of the number of sources that are not in the cache to the number of all accesses. The cache system can also be classified into a first level cache node and a second level cache node. The first level cache configuration is high, directly connecting to the source site, and the second level cache configuration is low. When a directly connected user returns to the source, the secondary cache will only find the primary cache, which returns to the source, effectively reducing the actual return to the source. Through the CDN’s load balancing system, intelligent scheduling of edge nodes provides services, which is equivalent to the brain of the CDN service, and the caching system is equivalent to the heart of the CDN. Cache hits are directly returned to users. CDN builds national and even global private networks, allowing users to access nearby edge nodes in the private network, reducing transmission delays, and achieving website acceleration.
In summary, CDN service quality indicators are also the “health status” of nodes, such as service capacity, bandwidth, and response time. Combining the above factors, it is necessary to obtain an appropriate edge node to improve its quality, and then this node is returned to the user. The user can access the nearby CDN cache proxy. The purpose of CDN is to improve the quality of Internet services, which in popular terms is to improve access speed.
