Thomas Camlong
fee2e6a6af
Four commits now apply the off-screen row treatment; only the first was A/B'd. Records
which is which, and warns how to read a result for the three widgets that do not overdraw
on the test backup - a measurement there will correctly show no change, because the benefit
only exists once an integration returns more rows than the tile can show.
Also records two things that look like gaps and are not:
- content-visibility was applied to five of the 26 ScrollArea widgets on purpose. It
costs containment work and can be wrong on self-measuring content such as charts and
the notebook, so the rule was: apply where list length is decided by remote data.
- React cache() is server-only. It already wraps getBoardByNameAsync, getHomeBoardAsync,
getRscServerSettingsAsync and getQueryClient; it does nothing for client widget
rendering, where react-query does the caching and its gcTime was already verified at
5 minutes rather than the 24 hours the original fix catalogue assumed.
Homarr performance investigation
Measured work on Homarr's memory and rendering cost, split by subject. Every figure here comes from
a run of scripts/benchmarks/stress-restore.mts against a restored real backup — 4 boards, 51
widgets, 11 integrations, driven through an actual login — not from a synthetic or empty container.
| document | subject |
|---|---|
| SERVER-MEMORY.md | What the container's RAM is made of, and the changes that reduced it |
| CLIENT-PERFORMANCE.md | Dashboard rendering cost in Chrome: DOM, fibers, images, paint |
| REJECTED.md | Ideas that were implemented and measured, then abandoned — with the numbers |
| METHODOLOGY.md | The tools, and the measurement traps that produced wrong answers |
| NEXT-STEPS.md | Handoff: what is unverified, what to do next, and the set for a clean PR |
Headline result
Server RAM, merge-base 06724cfeb vs this branch, two alternated runs per side, reported as cgroup
anonymous memory because that is what counts against a container limit and cannot be reclaimed:
| stage | before | after | change |
|---|---|---|---|
| peak | 376.6 MiB | 279.3 MiB | −26% |
| boot idle | 130.5 MiB | 62.4 MiB | −52% |
| after sign-in | 247.4 MiB | 142.9 MiB | −42% |
| dashboard loaded | 293.4 MiB | 170.4 MiB | −42% |
| 4 tabs, 2 boards | 366.5 MiB | 258.2 MiB | −30% |
| after 2 min idle soak | 323.7 MiB | 200.8 MiB | −38% |
No before/after range overlaps at any stage. The cost is +18% CPU (solid, non-overlapping).
The changes that did it, by ratio
| change | size | effect |
|---|---|---|
--max-semi-space-size=4 |
1 line | −19% idle, −21% peak |
preloadEntriesOnStart: false |
1 line | −52% anon at idle, 310 fewer files even at full load |
| Umami: stop fetching 100k raw events per refresh | 1 file | −26% peak, −93% transient buffers |
serverExternalPackages (mysql2/pg + 8 more) |
1 block | −21 MiB idle |
| ssh2's 16 MiB WASM heap (docker-modem patch) | 1 patch | −15 to −18 MiB external |
content-visibility on media-release cards |
4 lines | −59% image requests, −41% layout objects |
What is left, and why it is hard
One lever has real headroom and it pays twice. Roughly 41 MiB of retained bundle source and ~38 MiB of V8 compiler zone memory both scale with how much JavaScript the server loads and compiles, and the largest single contributor is a 16.10 MiB subtree reached by every API route — the tRPC router importing every integration eagerly. Reducing that reduces both.
Everything else has been measured and closed: see REJECTED.md.