Split header time from body-read time on the docs upstream - #1674
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fetch() resolves when headers arrive, so the earlier probe returned ~1ms without ever reading a body. Both genuinely slow operations read one: the docs proxy reads a 179KB page and the JWKS store calls hit.json(). Time headers and body separately on the exact upstream the docs proxy uses, gated to /robots.txt so normal traffic never pays for it.
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Cloudflare previewTorn down — the PR is closed. |
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Elimination so far, all measured in the same requests that took 3-11s wall:
preWorkMs0-4ms,cacheProbeMs2-21ms,timerProbeMs1ms,fetchProbeMsmedian 1ms, cpu 18-323ms.Everything generic is fast. But two app operations are genuinely slow, and both read a response body:
http.client GETtoexecutor.mintlify.dev— p50 3001ms from the Worker, while the same URL is 0.063-0.196s from a laptop (x-vercel-cache: HIT, 179KB) and a probe fetch to cloudflare.com from inside the same request is 1ms.workos.session.jwt_verify— p50 2895ms, whose only I/O is a Cache API hit plushit.json(), while a Cache API miss probe is 4ms.The earlier
fetchProbeMsnever read a body, which is why it looked fast. This times headers and body separately. Gated to/robots.txt.