Improve browser Total Blocking Time (TBT) performance of Project Merge Request Discussions page into S3 tier
The Project Merge Request Discussions page's browser Total Blocking Time (TBT) performance is unperformant:
* Environment: 10k
* Environment Version: 15.10.0-pre `ee389da2290`
* Date: 2023-03-08
NAME | FCP (ms) | LCP (ms) | TBT (ms) | SI (ms) | LVC (ms) | TFR SIZE (kb) | SCORE | RESULT
--------------------------------------|----------|----------------|-----------------|---------|----------|---------------|-------|-------
web_project_merge_request_discussions | 1465 | ✓ 1547 (<3500) | ✓ 5152 (<6000) | 2569 | 9600 | 1239.7 | 72 | Passed
The Project Merge Request Discussions page being tested can be seen here on Staging. This page is showing overview tab on MR page, below is the screenshot of page's historical test TBT results.
Test Details
Testing was done on our 10k Reference Architecture environment with our lab condition SiteSpeed pipeline (named GitLab Browser Performance Tool internally). The project being tested is a copy of gitlabhq (tarball can be found here). GitLab Browser Performance Tool tests information is listed at Current test details page.
The latest GitLab Browser Performance pipeline results can always be found here. Through this page the full SiteSpeed report can be found via the SiteSpeed Report
link on that page.
As per our performance targets this page's TBT metric is above the target of 2000 ms which is severity2. Task is to improve the page's browser performance into next tier.