The throughput bottleneck was curator-side, not the network. lease() claimed the
lowest-id pending/expired jobs with `... ORDER BY id LIMIT n`, but with only a
plain `status` index Postgres walked the primary key from id=1, skipping the
entire prefix of already done/error rows before reaching pending ones. As `done`
grew (69k+), every lease became an O(done) scan — leasing crawled, the DB
saturated, and even /status (the queue GROUP BY count) stalled the agent.
- Migration 0070 adds two partial indexes over just the live slice: pending rows
indexed by id (hot path), and leased rows by lease_expires_at (crash-recovery
+ orphan sweep). They stay tiny no matter how large the done/error history.
- lease() split into two phases so each uses a partial index: claim pending
first (id-ordered, O(batch)); reclaim expired leases only when pending can't
fill the batch. Same semantics (SKIP LOCKED, attempts++, expired reclaim).
- Model __table_args__ declares the indexes so ORM and schema agree.
- Test: a done-prefix at low ids must not stop the lease reaching pending.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ttrj5P7upUTueSfoJcxEqa
Answers "how are videos/all media handled by the GPU worker": a job is per ITEM,
but the agent fans a VIDEO into per-frame instances (ffmpeg in the agent, the
existing cadence), each stored with a timestamp — so a video becomes a BAG of
frame embeddings (fixes the mean-embedding muddle) instead of one washed-out
vector. Stills → frame_time NULL; animated GIF/WebP treated like short video.
- image_region.frame_time (migration 0061, not yet deployed so folded in): the
source frame's seconds for video/animated media; NULL for stills. RegionService
passes it through. A whole frame is just kind='frame'.
- gpu_job + GpuJobService (migration 0062): the durable work list that keeps the
desktop agent HTTP-only — enqueue (dedupes (image,task)) / lease (FOR UPDATE
SKIP LOCKED, re-claims expired leases so the queue self-heals) / heartbeat /
complete / fail (re-queues until MAX_ATTEMPTS then 'error'). The server enqueues;
the agent leases+submits over the web API; Redis/Postgres stay private.
Tests: enqueue dedupe, lease-then-skip-when-held, expired-lease reclaim, scoped
heartbeat, complete, fail-requeue-then-error. region test now covers frame_time.
NEXT: the thin HTTP API (lease/submit/heartbeat) + bearer-token auth, then the
agent container + control UI.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ttrj5P7upUTueSfoJcxEqa
bvandeusen