Fix telemetry span duration for request spans #70908
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What?
Fixes a bug where telemetry spans for Pages Router requests are way too short.
Why?
The
handleRequestImpl
function is wrapped withtracer.trace()
to trace the duration of Next.js handling a request. Thetracer.trace()
function immediately starts a span and ends it when the return value of the passed callback resolves.In the pages router
handleRequestImpl
more or less immediately resolves, even though the request is still being processed. The started span is immediately ended, not waiting forres.end()
, which should be the actual end timestamp of the span.How?
I adjusted the
tracer.trace()
function to take an optionalmanualSpanEnd
option, which will make thetracer.trace()
function not end the span when the promise resolves. Additionally, we now manually end the request span with theonClose
hook.Relates to #64723