Cache Hit Ratio
The cache hit ratio (CHR) measures how frequently user requests are served directly from CDN edge nodes. It is a core metric for evaluating CDN acceleration performance and node service capabilities. A higher CHR indicates that more requests are responded to by edge nodes rather than being fetched from the origin server. This significantly reduces the load on the origin server and speeds up user access.
CHR Types
A cache hit ratio can be a traffic hit ratio or a request hit ratio based on the statistical dimension.
- Traffic hit ratio = Amount of traffic served from cache/Total traffic
Total traffic = Traffic served from cache + Traffic generated during origin pulls
- Request hit ratio = Number of requests served from cache /Number of total requests
Differences Between CHR and Cache
Although closely related, CHR and cache represent different dimensions. Caching is the prerequisite. They both helps improve content delivery efficiency.
Caching is the process of storing copies of origin resources on CDN PoPs. It is the foundation of CDN acceleration.
CHR refers to the probability or proportion of user requests served by cached content. It quantifies CDN acceleration performance and efficiency.
CHR-related Operations and Features
To monitor and optimize CHR, you can:
- View the CHR: Hit Ratios
- Configure cache rules: CDN PoP Cache Rules
- Improve the CHR: Improving the Cache Hit Ratio
