Configure document-policy: js-profiling has a 30% impact on page load performance.

[HaoZhouInRC]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/react

SDK Version

8.27.0

Framework Version

16

Link to Sentry event

No response

Reproduction Example/SDK Setup

No response

Steps to Reproduce

Configure document-policy: js-profiling has a 30% impact on page load performance.

Expected Result

This exceeds the 5% impact mentioned in the document.

Actual Result

How should I optimize it?

[chargome]

Hi @HaoZhouInRC! Could you share how you measured this performance outcome?

[MercuryLiRC]

Hi @chargome We're gathering the performance tracing data and will be shared with you soon.

[MercuryLiRC]

After enabling JS-Profiling, multiple PerformanceLongAnimationFrameTiming entries appear during page refresh, causing significant time fluctuations.

Explanation of Metrics

• data.ready.messages.LoAFs
  Represents the value of LoAFs (PerformanceLongAnimationFrameTiming) in the context of a refresh. For detailed documentation, refer to the MDN Web Docs on PerformanceLongAnimationFrameTiming.

• data.ready.messages
  This is a business metric used to measure the loading time of our messaging service.

• data.ready.messages-LoAFs
  Represents the value of data.ready.messages minus LoAFs.

On

Metric	min	top50	mean	top90	max
data.ready.messages.LoAFs	3188	3743	3820.474	4378.2	4736
data.ready.messages	28244	30270	30155.316	31355.2	32921
data.ready.messages-LoAFs	24901	26286	26276.895	27286.4	28600

Off

Metric	min	top50	mean	top90	max
data.ready.messages.LoAFs	123	194	201.667	268.3	329
data.ready.messages	25706	27196	27599.736	29128.1	29717
data.ready.messages-LoAFs	25666	26986	27399.316	28962.8	29520