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AbhiPrasad
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Sep 9, 2025
Lms24
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Sep 12, 2025
…17562) Adds a few attributes to `resource.*` spans for request timing and status information. Most importantly: - `http.request.time_to_first_byte` [from `responseStart`](https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/responseStart) which can be [interpreted as TTFB](https://web.dev/articles/ttfb#measure-resource-requests) for resource requests. This was requested via via getsentry/sentry#63739. - `http.response.status_code` the status code of the resource request. Requested in #16805 and #10995 To get these attributes, I adjusted the already existing `resourceTimingToSpanAttributes` a bit: - Moved it from browser to browser-utils because resource spans logic is located in browser-utils (this is safe, it never was exported from browser) - Changed the signature to return an object instead of an array of attributes. This is more ergonomical to use in both callsites and should reduce bundle size slightly - Added `http.request.redirect_end`, `http.request.worker_start` attributes which are stable timing values available on `PerformanceResourceTiming` but were previously missing - Also added to conventions: getsentry/sentry-conventions#130 - Added `http.request.time_to_first_byte`. Decided to add this attribute because `http.request.response_start` cannot be directly used as TTFB as its value is an absolute time stamp of `responseStart`. Instead the TTFB attribute is the relative response start attribute converted to seconds (happy to change to ms if reviewers prefer). - Also added to conventions: getsentry/sentry-conventions#131 Other consequences: - `http.client` spans now also have the three additional attributes Remarks: - Not super happy about us always defaulting to `0` in case a value is not present. But decided to leave this as-is to avoid any behaviour change for http.client spans.
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This PR adds the following attributes:
http.request.worker_starthttp.request.redirect_endwhich are timestamps in the browsers request lifecycle model but were missing from our conventions.
These attributes will be collected from to the browser JS SDK once getsentry/sentry-javascript#17562 is merged.
Note: I realized a lot of other request timing values are marked as
type: integer. However, the browser SDK returns floating point numbers (milliseconds divided by 1000), so I think they should rather betype: double. Will open a separate PR with fixes.