<b>This week in caching: chasing hit ratio</b>

<b>This week in caching: chasing hit ratio</b>
Your CDN bill and TTFB both track this number. Reads:
— <i>Reading the CDN cache-status header</i> — decoding HIT/MISS/EXPIRED/STALE and the newer standardized Cache-Status header.
— <i>Why your ratio is lower than you think</i> — the long tail of rarely-requested URLs that never get a second hit (tiered caching as the answer).
— <i>Compression and caching order</i> — caching pre-compressed vs compressing per response, and why getting it backwards wastes CPU.
— <i>Cache hit ratio vs cache offload</i> — the two metrics people conflate; one can look great while the other is terrible.
Credits: the Fastly and Akamai measurement guides.
Bookmark: the standardized Cache-Status header explainer — finally a portable way to debug across CDNs.