High page load times and tab crashes when loading long Sentry Replays

[dalnoki]

Environment

SaaS (https://sentry.io/)

Steps to Reproduce

A customer recently observed a significant performance regression in Sentry’s Replay feature. Replays that used to load and play back smoothly are now taking an excessive amount of time to load, and in many cases the browser tab becomes unresponsive or crashes entirely when attempting to load longer sessions.

1. Generate a long Replay
2. Open it in Sentry

example: https://cambai.sentry.io/replays/af033d21b79c426f82a3b80448313bd5

Expected Result

The replay should begin loading within a few seconds and remain responsive

Actual Result

Initial load time exceeds 30 seconds on average and the browser tab often freezes or crashes before the replay fully loads.

Product Area

Replays

Link

No response

DSN

No response

Version

No response

[getsantry]

Routing to @getsentry/product-owners-replays for triage ⏲️

[getsantry]

Auto-routing to @getsentry/product-owners-replays for triage ⏲️

[ryan953]

The linked replay has about 300 click breadcrumbs over 30+ mins. It's mid-high but not toooo many. What could be worse is that it's 5mb of data including 3 "too many mutation" warnings. So chugging through all that is a lot.

More profiling will reveal more detail.

[nihaalnz]

Any status on this? What is the next step?

[billyvg]

We know where the problem is but we're still working on a fix. As a temporary workaround, you can load any tab aside from Breadcrumbs, and the replay will play correctly. (e.g. open Console and then refresh the page).

[billyvg]

@dalnoki this is now fixed for the linked org, I'm not closing this issue yet as there are still issues with another org

[nihaalnz]

@dalnoki this is now fixed for the linked org, I'm not closing this issue yet as there are still issues with another org

By fixed, do you mean fixed up to the production version?

[billyvg]

@dalnoki this is now fixed for the linked org, I'm not closing this issue yet as there are still issues with another org

By fixed, do you mean fixed up to the production version?

@nihaalnz Correct, let me know if you're still having issues