Follow these steps to find out why your Alibaba Cloud CDN cache hit rate drops.
Is the cache refreshed?
If the cache is refreshed, the hit rate may be decreased in a short time.
Is the bandwidth suddenly increased? And are all accesses to the server from new URLs?
When the bandwidth is increased suddenly or there are many accesses to the server from new URLs, many requests are carried back to the origin site and the hit rate is decreased.
Is any new content published on the origin site?
When the Alibaba Cloud CDN node accesses new contents, many requests are carried back to the origin site and the hit rate is decreased.
Are there more 5XX and 4XX messages due to exceptions on the origin site?
Because 5XX and 4XX messages are not cached, the hit rate is decreased.
Is the header parameter of the access URL of the origin site, or the cache configuration rule on the Alibaba Cloud CDN console changed?
The hit rate may change if the cache duration is adjusted.