Operator-flagged on the deployed .5 build: the autoscaler grew the pool 1→8
against an EMPTY queue (an empty buffer read as 'GPU starving' regardless of
WHY), and every downloader kept polling lease every 10s all night.
- New idle signal straight from the lease results: an empty lease sets _idle,
any jobs clear it. The occupancy-low branch now distinguishes three cases:
queue empty → shed to ONE polling downloader; pinned at the bandwidth cap →
shed toward 3; cap headroom + work flowing → grow.
- Idle lease polls back off exponentially per downloader to
IDLE_POLL_MAX_SECONDS (15 min) and reset the moment work appears — so an
idle night costs one HTTP call per 15 min, and new work is noticed within
at most ~15 min (operator-accepted trade-off).
- UI hint: 'idle — queue empty, lease poll backed off'; /status gains idle.
Agent build 2026-07-02.6.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CDgx8bQS5YrGRK76v8HUnM
bvandeusen