4 Commits

Include renames

Author	SHA1	Message	Date
bvandeusenandClaude Opus 5	5b6f2ba526	fix: a Postgres connection was held across every celery round trip (4295) ... Operator, 2026-09-23: *"something about changing the cap number is blocking to the website... it shouldn't be"*. Nothing here was slow in itself. A database connection was held across work that is slow, and that is why it surfaced as the whole site stalling rather than as one slow page. `lane_view` took the session and kept it open through a celery inspect whose budget is 11s. The System tab polls that endpoint every 15s — and with a lane not answering, every inspect runs to nearly its full budget, so each poll pinned a connection for most of the interval. SQLAlchemy's default pool is 5 plus 10 overflow. Two browser tabs, `/api/system/health` doing the same thing, and a cap change adding two more inspects exhausts it, and every OTHER request then waits for a connection. Split so the database work finishes before the broker work starts: - `lane_settings(session)` reads the caps and the oldest running task, then the session closes. `lane_view(settings)` does the inspect with none held. - `store_lane_cap(session, …)` validates and commits, then the session closes. `push_lane_cap(lane, …)` does the live push with none held. And a second finding while measuring it: **raising a cap now costs no broker round trip at all.** The first cut only knew on/off, so it inspected on every raise to find out whether the pool needed lowering — the control meant to be instant still waited out an inspect. `store_lane_cap` returns the PREVIOUS cap so the push knows the direction; only a lowering needs to say anything. The guard is structural, not timed: `lane_view` and `push_lane_cap` must not ACCEPT a session. A timing test would be flaky, and a call-order test would pass against a version that took the session and merely used it early. `/api/system/health` has the same shape and is NOT fixed here — it is rate-limited by `refresh_if_stale` so it does not inspect on every request. Worth doing, separately. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR	2026-09-23 14:52:36 -04:00
bvandeusenandClaude Opus 5	445164c852	feat: one number per lane — the cap — and the autoscaler is the mechanism (4295) ... Operator, 2026-09-23: *"auto should be always on, not a setting, so that idle instances quiet down when not running. the number that is visible and something the user can tweak and manage should be the cap itself the number of running workers is handled by the autoscaling function which is always on."* They are right, and the reason it was not built this way is worth stating: the manual dial came first (steps 2-4) and the autoscaler came last (step 7), as an opt-in BESIDE a control that already existed. Nothing ever asked whether the dial should still exist once something could move it automatically. Each step was defensible; the result was three operator settings over one number. ## `slots`, `enabled` and `autoscale` are gone `slots` was a MEASUREMENT wearing a preference's clothes. How many workers a lane runs is read live and moved every minute; storing it meant the operator had to keep two numbers in agreement and the autoscaler had to be told it was allowed to touch one of them. `autoscale` gated the mechanism behind a choice, so a lane nobody opted in never gave its workers back — which is why an idle instance never quieted down. `enabled` is derived: a cap of zero means no consumers. "Off" and "may use no workers" were two spellings of one fact, stored separately, free to disagree. ## Two sweeps become one `reconcile_lanes_sync` drove the pool to the stored `slots`; `autoscale_lanes_ sync` moved it away from that same number; and most of step 7's hardest reasoning — a stored value that is a FLOOR, a target of `max(stored, current)` — existed only to stop them fighting. Delete the stored number and the problem is not solved, it is absent. `size_lanes_sync` runs every minute and owns both consumers and pool size. It also subsumes what the reconcile was for: a worker restarted at its ENV concurrency is corrected on the next tick rather than after five. Growth is immediate, shrink is one worker per tick. Deliberately asymmetric — "always on" is only pleasant if the ramp keeps up, and +1/minute would take four minutes to answer a burst. Being one worker too large for a minute costs a sleeping process; being too small costs work not happening. For ML the asymmetry matters most: every new slot reloads a multi-GB model, so the slow shrink is what stops a quiet patch from paying that cost again a minute later. ## The caps ship at one, and zero for ML Per the operator. Conservative on purpose — and a conservative default nobody knows how to raise is just a slow product, which is the other half of what they asked for: "there needs to be something that tells the user to bump those numbers to improve processing rate or they'd never know the controls exist." So a lane running everything its cap allows while work piles up says so, in its own row, with the headroom named: *"4,060 waiting and all 1 worker busy. Raise the cap to run more at once — this machine allows up to 7."* It fires only when raising the cap would actually help. Not when the lane is keeping up, not when the sizing pass has room it has not taken, and not at the machine ceiling — where "raise the cap" is advice nobody can take. ## Migration 0105 rewrites the caps rather than carrying them The old defaults (4/2/2/1) bounded a manual control and were loose because moving within them was the ordinary act. The number now means "the most workers this lane may use", which is a different promise; carrying the old figure over would quadruple the worker lane on every existing install at the moment this deploys. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR	2026-09-23 12:48:22 -04:00
bvandeusenandClaude Opus 5	a01165365b	feat: a saturated lane can grow itself, within the cap the operator set (4297) ... Milestone 422 step 7 — the one sweep in this milestone that decides rather than obeys, so it is off until a lane is opted in, bounded by the operator's cap, floored at the operator's value, and it reports every decision including the ones where it did nothing. Growth needs BOTH halves: all slots busy AND a backlog. Depth alone means celery is about to pick those up and growing would add idle children (#1253 is that bug in the GPU agent); saturation alone means the lane is busy with exactly as much work as exists. The backlog is depth PLUS reserved, because celery prefetches and LLEN reads 0 while a worker holds thirty tasks in memory — the case an LLEN-only autoscaler misses entirely, and the reason step 2 plumbed `reserved` through. The two sweeps had to be taught not to fight. The reconcile drives every lane to its stored slots every five minutes, which would have reverted each grow on the next tick: grow, revert, grow, revert, forever. For an autoscaling lane the stored value is now a FLOOR — restored when a lane falls below it, never taken back above it. The operator's "a task that runs for x concurrent time" idea stays a UI warning rather than a trigger: a long task does not finish sooner because the lane gained a slot, so scaling on it would spend memory to change nothing. Read from `task_run` on our own wall clock, not celery's `time_start`, which is the WORKER's monotonic clock and would produce a duration that is meaningless in the direction that matters — plausible. Caught while reading it back: the first version read the stored slots as the CURRENT pool. The autoscaler never writes that row, so every tick would have proposed floor+1 — resizing nothing, reporting `grew` anyway (a replica already past the target is issued no message and reports success), and capping the lane one slot above its floor forever while claiming otherwise. It now reads the live pool and keeps the stored value purely as the floor, and the tests fix the two to different numbers so an equal-fixture pass cannot hide it again. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR	2026-09-22 10:05:43 -04:00
bvandeusenandClaude Opus 5	a9c1b421a7	feat: change a lane's slots on a running system, over the broker (4292) ... Milestone 422 step 2. `GET /api/system/workers` reports every lane joined to its live pool; `POST /api/system/workers/<name>` changes it. NO DOCKER SOCKET. Milestone 365 deferred "acting on the state" because restarting a dead worker needs a socket the web container deliberately does not have. That holds for restarting a CONTAINER; it does not hold for changing how much work a RUNNING worker does. celery's pool_grow / pool_shrink / add_consumer / cancel_consumer send a message over the Redis the app already uses, and the worker resizes itself. No new privilege, no new surface, and the security question that deferred this is never raised. PERSIST AND PUSH, in one call, in that order. pool_grow is not durable — a restart drops every lane to its env concurrency — so a UI that only pushed would lose the setting on the next deploy with nothing to show for it (lesson #4202). Storing alone would describe nothing until something restarted. A failed PUSH is not a failed setting: 200 with `applied: false` and a reason, so the UI says "saved, not yet live" rather than "that didn't work". Step 3's reconcile carries it when the lane answers again. PER-REPLICA DELTAS. `pool_grow(n, destination=[...])` adds n to EACH destination, so while `worker` runs `replicas: 2` a single delta from an aggregate is wrong for both. `slots` therefore means what CELERY_CONCURRENCY means — one process's pool — and each replica is driven to it from its OWN current size, so replicas that drifted apart converge rather than moving in lockstep. I wrote this wrong first: the docstring claimed per-replica while the code computed one delta from the max across replicas. LaneLiveState now carries `pools` per hostname and exposes `pool` as a property. A replica already at the target is sent nothing at all — the reachable fixed point step 3's periodic reconcile needs, or it re-issues a grow of zero every tick forever (lesson #4183). A replica that answered inspect but not stats is NAMED in the error rather than skipped silently, since otherwise it would run at a size the UI claims it does not. `present=False` is not "zero slots", it is "nothing answered" — kept distinct throughout, because step 3 skips an absent lane rather than correcting it. /workers now also reports pool size (from `insp.stats()`) and RESERVED count. Celery prefetches, so tasks that have left the Redis list but not started are invisible to LLEN: a lane can read depth 0 with thirty tasks held in worker memory. `pending` is depth + reserved. The UI is misleading without this and step 7's autoscaler would be simply wrong. Also kills the THIRD copy of the queue list: system_activity's _QUEUE_NAMES, whose own comment admitted the coupling ("must match celery_app.task_routes") and which sat alongside task_routes and the ROLE_NAMES copy step 1 collapsed. Now derived from LANES. The rendered order changes to lane grouping, which is the better shape for a lane-oriented UI. Separate blueprint rather than folding into system_activity, which states in its first line that it is read-only and answers a different question — its /workers is keyed on celery HOSTNAME and reports which nodes answered. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR	2026-09-22 08:01:23 -04:00