The download/edit child (yt-dlp + ffmpeg) shares one LAN box with the API,
Postgres, and Plex playback. A CPU re-encode pegged every core for ~30s and
starved web requests + playback until it finished. Full-scope S4 mitigations:
- Child self-de-prioritizes at startup (inherited by every ffmpeg/yt-dlp
descendant): CPU nice increment + best-effort idle ionice class + an
OMP_NUM_THREADS budget, all config-gated and independently disable-able.
- Cap the browser-safe re-encode's encoder threads (`-threads`) so a transcode
reserves a core for foreground work instead of claiming all of them.
- Throttle the retention GC's whole-tree orphan sweep (yield IO after each
batch of files) so its rglob can't monopolize disk IO in the API process.
- Idle-back-off the Download Center (2s→15s when nothing queued/running) and
UsageBar (2s→15s when running_jobs is 0) polls; both snap back to 2s on the
next fetch after an enqueue (invalidateDownloads refetches immediately).
Tests: encode_thread_cap (pin/reserve-core/edge), -threads flag presence,
_deprioritize (nice/ionice/OMP branches), GC sweep throttle batching.
Follow-up to user prod testing of 0.51.0:
- re-download now clears job.display_name so the card title + Content-Disposition filename are
re-derived from the freshly-cleaned title (previously an auto-name from an older un-cleaned
title — still carrying a "… views · … reactions |" prefix — survived the rebuild).
- on-disk AND served names are now a strict shell-safe slug: only [A-Za-z0-9._-] survive; every
other char (the "!" the user saw, plus ( ) [ ] & $ ' " ; | ? * …) collapses to "_". The id no
longer uses [brackets] (glob metacharacters). Shared _slug helper for sanitize + display_filename.
- GC gains a 5th pass: sweep on-disk files/dirs no ready asset owns (old accented channel dirs, a
poster from a superseded naming scheme left after a re-download), skipping the dot system trees
and anything newer than an hour so an in-flight download is never touched.
- Tests: slug strips !/$/()[]; rel_path is bracket-free; orphan-sweep keeps owned/system/fresh files.
Verified each deferred per-subsystem item against current source, then fixed the
real ones (tradeoffs left as-is, see siftlode-ops/CODE-HYGIENE.md closeout):
- search BUG-3: don't finalise shorts_probed on un-enriched stubs (enrichment
failure/omitted rows) — restores the scheduler's enriched_at guard so a real
Short can't leak into the feed and never get reclassified.
- downloads GC: 4th pass reaps orphaned errored, fileless, unreferenced assets
(they carry no TTL, so the expiry passes never cleared them).
- downloads B6: quota/edit errors now return a structured {code,reason,limit}
the trilingual client localises, instead of hardcoded English + dot-decimal GB.
- channels BB1: reset-backfill re-arms deep sync on every subscriber (bulk update)
instead of 404ing when the admin isn't personally subscribed.
- channels BB2: enrich the stub on BOTH the normal and "already exists" desync
path (nest the insert try inside the client `with`).
- channels CB3: drop the redundant second _discovery_rows read (identity-mapped
rows are already enriched; re-sort in Python for the title tie-break).
- playlists PC1: read the live playlist once in push() and share it with plan_push
+ push_playlist (halves read-quota, closes the second TOCTOU window).
- playlists PC2/PC5: batch the cover thumbnails in one window query (was N+1);
rename combines count+duration into one aggregate + a single cover lookup.
- messages MB2: get_thread only resolves a messageable partner OR one we already
share a thread with (closes the user-enumeration oracle).
- messages MB3: push a live unread-count to the user's other tabs after mark-read.
- messages MC4: list_conversations uses DISTINCT ON + grouped COUNT instead of
loading the whole message history into memory.
- config AB3: per-spec allow_empty so smtp_user/youtube_api_proxy can be blanked
to disable them rather than snapping back to the env default.
peter