APO uses two-layer caching: regular Cache and KV. We get the best of two worlds:
- faster responses when local Cache has content.
- serving content from KV instead of going to the origin on Cache miss.
In a nutshell, it is a DIY version of Cloudflare Tiered Caching with Generic Topology. Internally we discussed if APO should utilize Tiered Caching technology instead of Local Cache + KV. With the growing usage metrics, it becomes clear the question is not if but when.
I’m excited to say we are starting to test APO tiered caching (HTML only) in a limited capacity in some colos around the world.
We expect no visible changes to APO customers, though some side effects could happen.
Expected effects of Tiered Caching:
- slight changes in Cache hit ratio
- decrease the load on origin servers
- faster p95 response times for APO sites.