Rewrite null pyworker on the framework session model
Drop the held-/reserve approach in favour of the framework's session
primitive (max_sessions=1 + /session/create). Sessions are excluded from
the autoscaler's queue-wait math and don't suffer the cur_perf=0
degradation that a long-held request did, so this naturally produces the
"one request comes in and you get a worker; release and it scales back
down" model we were hand-rolling.
Server side:
- max_sessions=1; framework auto-registers /session/* routes
- Drop custom /reserve handler, _active_reservation event, max_queue_
time=0.0, MAX_RESERVATION_SECONDS, _perf_heartbeat
- Trivial /ping handler exists only to satisfy the framework's
"at least one handler with BenchmarkConfig" requirement (and to give
clients an extension/keepalive route)
- /release on the internal control port is kept as a convenience for
queue consumers that don't carry session_auth — calls the framework's
__close_session via name-mangling, which bypasses the session_auth
check but is fine for a localhost-only endpoint
- Workload/perf back to 100 (conventional)
Client side:
- Uses endpoint.session(cost, lifetime) instead of POST /reserve
- async with the SDK Session; close on exit posts /session/end with
proper auth → 200 success in metrics
- Demo and single modes both ride the same reserve() helper
Sessions landed in vastai-sdk 0.4.2 (commit ec9ef59, 2026-01-20).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
+90
-94
@@ -1,10 +1,8 @@
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# Null PyWorker
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A PyWorker that does **nothing** — it does not forward requests to any model
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server. Each HTTP POST to `/reserve` simply marks the worker as busy and holds
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the request open until the user's queue consumer (running locally on the
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instance) calls `/release` on the internal control port — or a safety
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timeout elapses.
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server. Reservations are modelled as framework **sessions**: a request
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comes in and you get a worker; release and it scales back down.
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## When to use it
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@@ -15,32 +13,29 @@ Use this worker when you want to drive Vast Serverless autoscaling but you do
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etc.).
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- A separate worker process on the Vast instance pulls work from that queue
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directly. The Vast PyWorker is not involved in the request/response path.
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Your consumer can be any language — node, golang, python, a binary —
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this PyWorker is implementation-agnostic.
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- You want one Vast worker per active queue consumer, and you want the
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Serverless autoscaler to spin instances up and down based on demand on
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*your* side.
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A request comes in and you get a worker. Release and it scales back down.
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POST to `/reserve` and serverless gives you a worker, held busy for the
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lifetime of the request. When your queue consumer is done, POST to
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`/release` on the internal port (`127.0.0.1:18999` by default) and the
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held `/reserve` returns `200`.
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## How it works
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- `allow_parallel_requests=False` and `max_queue_time=0.0`, so one in-flight
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`/reserve` fully occupies the worker and any further request that lands
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on it is rejected with `429` immediately — serverless will route to a
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free worker or scale a new one up.
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- `lifecycle` is used instead of `model_log_file`, so there is no log to tail
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and no model server to start. The worker reports itself ready immediately
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after the (trivial) benchmark.
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- The `/reserve` handler is a `remote_function` rather than an HTTP proxy, so
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the framework never tries to forward the request anywhere — it just awaits
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an internal `asyncio.Event`.
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- An internal aiohttp control server, bound to `127.0.0.1`, hosts
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`/release` (and, when no external healthcheck URL is provided, a stub
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`/health`).
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- Reservations use the framework's **session** model. The SDK exposes
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`endpoint.session(cost, lifetime)` which POSTs to `/session/create` (a
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built-in framework route) and returns a `Session` object usable as
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`async with`. Closing the context (or calling `await session.close()`)
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POSTs to `/session/end` — counted as a normal success in metrics.
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- `max_sessions=1` on the worker side means a second `/session/create`
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against an already-occupied worker returns `429`. Serverless routes
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that request to a free worker or scales a new one up.
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- Sessions are **excluded from queue-wait math** (the framework filters
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`if not request.is_session`), so an occupied worker doesn't look like
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it has a request queue piling up. The autoscaler treats a session as
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occupancy, not as work-in-progress.
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- `lifecycle` is used instead of `model_log_file`, so there is no log to
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tail and no model server to start. The worker reports itself ready
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immediately after a trivial benchmark.
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## Healthchecking
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@@ -49,48 +44,52 @@ fails after the first success, the worker is marked errored and the
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autoscaler can decommission it. Two modes:
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- **Stub (default)** — the internal control server also answers
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`GET /health` with `200`. This is just enough to satisfy the framework
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while you wire up real consumers.
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`GET /health` with `200`. Just enough to satisfy the framework while
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you wire up real consumers.
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- **Point at your queue consumer (recommended)** — set
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`BACKEND_HEALTH_URL=http://127.0.0.1:9090/health` (absolute URL) and the
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pyworker will healthcheck *your* consumer instead. If your consumer
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`BACKEND_HEALTH_URL=http://127.0.0.1:9090/health` (absolute URL) and
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the pyworker will healthcheck *your* consumer instead. If the consumer
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process crashes, the autoscaler will see the worker as broken.
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Run your queue consumer on the instance alongside the PyWorker, expose a
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plain `/health` endpoint on it, then set `BACKEND_HEALTH_URL` accordingly in
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your template.
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## API
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### `POST /reserve` (external port, signed by the autoscaler)
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### Reservation: `POST /session/create` (external, signed)
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Holds the worker busy until the reservation ends.
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Not implemented here — the framework provides this route automatically on
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every PyWorker. Use the SDK:
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Request body (all fields optional):
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```python
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from vastai import Serverless
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```json
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{ "duration": 600 }
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async with Serverless() as client:
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endpoint = await client.get_endpoint(name="my-null-endpoint")
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async with endpoint.session(cost=100, lifetime=600) as s:
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# Worker is now reserved. Your queue dispatcher does whatever it
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# needs to do (typically: enqueue a job that mentions s.session_id).
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...
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# `async with` exit posts to /session/end → 200 success in metrics
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```
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- `duration` (seconds, optional): safety cap on how long to hold the
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reservation if no `/release` arrives. Capped by `MAX_RESERVATION_SECONDS`
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(env var, default 3600). If omitted, defaults to that cap.
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Or raw HTTP (the SDK takes care of autoscaler signing for you, but the
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shape of the request is documented for non-Python clients):
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Behavior:
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```
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POST /session/create
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{
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"auth_data": { /* signed by autoscaler */ },
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"payload": {
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"lifetime": 600,
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"on_close_route": "https://your.callback/notify",
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"on_close_payload": {"job_id": "..."}
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}
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}
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```
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- Returns `200` with `{"released": "explicit", ...}` when the local consumer
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POSTs `/release` on the internal port. **This is the intended happy path
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— the request is counted as a success in metrics.**
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- Returns `200` with `{"released": "duration_elapsed", "duration": <n>}` if
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the duration cap fires (safety net for a stuck consumer).
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- Returns `499` if the external client disconnects (counted as cancelled in
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metrics — avoid this; use `/release` instead).
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- Returns `429` immediately if the worker is already holding a reservation
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(so serverless routes the request to a free worker instead of queueing).
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### Release from a local consumer: `POST /release` (internal, localhost-only)
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### `POST /release` (internal port, localhost-only)
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Marks the active reservation as done. No body required. Idempotent:
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Closes the active session, regardless of who created it. No body, no
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auth. Use this when the queue consumer doesn't have (and shouldn't need)
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the session's `session_auth`:
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```bash
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curl -X POST http://127.0.0.1:18999/release
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@@ -98,78 +97,75 @@ curl -X POST http://127.0.0.1:18999/release
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Responses:
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- `200 {"released": true}` — active reservation was released; the held
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`/reserve` will return `{"released": "explicit"}`.
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- `200 {"released": false, "reason": "no active reservation"}` — nothing was
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in flight, no-op.
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- `200 {"released": true, "session_ids": ["..."]}` — closed; the held
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client-side `/session/create` completes and counts as a success.
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- `200 {"released": false, "reason": "no active session"}` — nothing
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active, no-op.
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Only processes on the Vast instance can reach this port. There is no
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authentication on it.
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For setups where the dispatcher can hand the consumer `session_auth`
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(e.g. as part of the queue payload), the consumer can instead POST
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`/session/end` on the framework's HTTP-only port
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(`$WORKER_HTTP_PORT`, default `WORKER_PORT+1`) — the standard, fully
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authenticated release path.
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## Environment variables
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- `MAX_RESERVATION_SECONDS` — upper bound on how long a single `/reserve`
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call can hold a worker if `/release` is never called. Defaults to `3600`.
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- `BACKEND_HEALTH_URL` — absolute URL the framework should healthcheck
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(e.g. `http://127.0.0.1:9090/health`). When set, the stub `/health` route
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is not registered on the internal server. When unset, the built-in stub
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is used.
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(e.g. `http://127.0.0.1:9090/health`). When set, the stub `/health`
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route is not registered on the internal server.
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- `NULL_CONTROL_PORT` — port for the internal control server (hosts
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`/release` and optionally `/health`). Defaults to `18999`.
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## Deploying on Vast Serverless
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1. Create a Serverless endpoint and point `PYWORKER_REPO` at this repository
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(or your fork).
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1. Create a Serverless endpoint and point `PYWORKER_REPO` at this
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repository (or your fork).
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2. Set `BACKEND=null` in the template so `start_server.sh` runs
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`workers.null.worker`.
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3. There is no model server to configure; you can omit model-related env vars
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entirely.
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3. There is no model server to configure; you can omit model-related env
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vars entirely.
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4. Run your own queue-consumer process on the instance alongside the
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PyWorker. When the consumer finishes its work it should:
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PyWorker. When it finishes its work:
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```bash
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curl -X POST http://127.0.0.1:18999/release
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```
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so the held `/reserve` returns success and the autoscaler can scale the
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worker down cleanly.
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## Client example
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Single reservation:
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Single reservation (holds for 180s):
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```bash
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python -m workers.null.client --endpoint <ENDPOINT_NAME> --duration 600
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python -m workers.null.client --endpoint <ENDPOINT_NAME>
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```
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To exercise the full flow, shell into the worker and run
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`curl -X POST http://127.0.0.1:18999/release` — the client returns with
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`{"released": "explicit", ...}`.
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Staggered demo:
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```bash
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python -m workers.null.client --endpoint <ENDPOINT_NAME> --demo
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```
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Starts three reservations 30s apart (all held concurrently), holds the
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Starts three sessions 30s apart (all held concurrently), holds the
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3-worker plateau for 5 minutes so the autoscaler has time to actually
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provision the third worker before any scale-down starts, then scales
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down one worker at a time, also 30s apart, and exits.
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provision the third worker before any scale-down starts, then closes
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the sessions one at a time, also 30s apart, and exits. Every session
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ends cleanly via the SDK's `session.close()` — `200` successes in
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metrics, no cancellations.
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Each reservation ends via its duration cap (a 200 success in metrics).
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Tune the timing with `--interval` and `--plateau`.
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Tune the timing with `--interval` and `--plateau`. To exercise the
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local-release path, shell into a worker and run
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`curl -X POST http://127.0.0.1:18999/release`.
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## Notes and caveats
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- The HTTP connection from the external caller must stay open for the full
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reservation. Make sure your client and any intermediate proxies allow
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long-lived requests (disable idle timeouts, retries, and connection
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reuse if necessary).
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- If your client retries on timeout, you may end up provisioning duplicate
|
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workers. Configure `duration` generously and rely on `/release` from the
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consumer to end reservations promptly.
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- Avoid disconnecting the external `/reserve` request as a way to release —
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that produces a `499` and is counted as a cancellation in Vast metrics.
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Always release via `POST /release` on the internal port.
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- There is no streaming / heartbeat in the response; the request returns
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exactly once, when the reservation ends.
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- The reservation's lifetime caps how long the session can live without
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client activity. Set it comfortably longer than the work you expect to
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do, or have the client periodically POST `/ping` with `session_id` to
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extend.
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- The `on_close_route` payload (passed at `/session/create`) is POSTed by
|
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the framework when the session ends. Useful for notifying your queue
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consumer that the reservation is closing.
|
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- `/release` on the internal port is convenient but bypasses
|
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`session_auth`. If you need the standard authenticated release flow,
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pass `session_auth` to your consumer (e.g. through the queue payload)
|
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and have it POST to `/session/end` on the framework's HTTP port
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instead.
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+42
-33
@@ -15,35 +15,42 @@ logging.basicConfig(
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log = logging.getLogger(__file__)
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ENDPOINT_NAME = "null-prod"
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SESSION_COST = 100
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async def reserve(
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client: Serverless,
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*,
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endpoint_name: str,
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duration: float,
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label: str = "reservation",
|
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) -> dict:
|
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"""Hold a Vast worker open for `duration` seconds (or until we disconnect).
|
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hold_for: float,
|
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label: str = "session",
|
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) -> None:
|
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"""Open a session, hold the worker for `hold_for` seconds, close cleanly.
|
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|
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The worker counts itself busy for the lifetime of this call. Returning
|
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here means the reservation has ended — either /release was called on
|
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the worker's internal control port, or the duration cap fired, or the
|
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HTTP request was cancelled.
|
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Uses the framework's session model — each session counts as one worker
|
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occupied, but unlike a held HTTP request it isn't poisoning the
|
||||
worker's throughput math. max_sessions=1 on the worker side means a
|
||||
second /session/create against the same worker gets 429, so serverless
|
||||
routes the second reservation to a free worker or scales a new one up.
|
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"""
|
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endpoint = await client.get_endpoint(name=endpoint_name)
|
||||
payload = {"duration": duration}
|
||||
# Session lifetime must outlast the hold. The framework expires sessions
|
||||
# whose `expiration` (set to now + lifetime at creation) has passed; we
|
||||
# don't make any keepalive requests so no extension happens.
|
||||
lifetime = hold_for + 60
|
||||
start = time.monotonic()
|
||||
log.info("[%s] POST /reserve duration=%ss", label, duration)
|
||||
log.info("[%s] creating session (lifetime=%.0fs, hold=%.0fs)", label, lifetime, hold_for)
|
||||
async with endpoint.session(cost=SESSION_COST, lifetime=lifetime) as s:
|
||||
log.info("[%s] session %s open", label, s.session_id)
|
||||
try:
|
||||
resp = await endpoint.request("/reserve", payload, cost=150)
|
||||
elapsed = time.monotonic() - start
|
||||
log.info("[%s] returned after %.1fs: %s", label, elapsed, resp.get("response"))
|
||||
return resp["response"]
|
||||
await asyncio.sleep(hold_for)
|
||||
log.info("[%s] hold complete, closing session", label)
|
||||
except asyncio.CancelledError:
|
||||
elapsed = time.monotonic() - start
|
||||
log.info("[%s] cancelled after %.1fs (HTTP connection dropped)", label, elapsed)
|
||||
log.info("[%s] cancelled after %.1fs, closing session", label, elapsed)
|
||||
raise
|
||||
elapsed = time.monotonic() - start
|
||||
log.info("[%s] session closed cleanly after %.1fs", label, elapsed)
|
||||
|
||||
|
||||
async def run_demo(
|
||||
@@ -53,38 +60,41 @@ async def run_demo(
|
||||
interval: float,
|
||||
plateau: float,
|
||||
) -> None:
|
||||
"""Trapezoidal load: ramp up three reservations, plateau, then scale down.
|
||||
"""Trapezoidal load: ramp up three sessions, plateau, then scale down.
|
||||
|
||||
Start three reservations spaced `interval` seconds apart. Pick the
|
||||
duration so that the first release fires `plateau` seconds *after the
|
||||
last reservation started*, giving the autoscaler time to actually have
|
||||
all three workers running before any of them begin to scale down.
|
||||
Releases then fire `interval` seconds apart, matching the ramp-up.
|
||||
Start three sessions spaced `interval` seconds apart. Each holds for
|
||||
`(n-1)*interval + plateau` seconds, so the first release fires
|
||||
`plateau` seconds after the last session started — giving the
|
||||
autoscaler time to actually have all three workers running before any
|
||||
scale-down begins. Releases then fire `interval` seconds apart,
|
||||
matching the ramp-up.
|
||||
|
||||
Each reservation ends via its duration cap (a 200 success).
|
||||
Each session ends via the SDK's `session.close()` on `async with` exit,
|
||||
which posts to /session/end with proper auth — counted as a normal
|
||||
success in metrics.
|
||||
"""
|
||||
n = 3
|
||||
hold = (n - 1) * interval + plateau
|
||||
tasks: list[asyncio.Task] = []
|
||||
for i in range(1, n + 1):
|
||||
label = f"res-{i}"
|
||||
log.info("[%s] starting (auto-release after %.0fs)", label, hold)
|
||||
log.info("[%s] starting (hold=%.0fs)", label, hold)
|
||||
task = asyncio.create_task(
|
||||
reserve(
|
||||
client,
|
||||
endpoint_name=endpoint_name,
|
||||
duration=hold,
|
||||
hold_for=hold,
|
||||
label=label,
|
||||
),
|
||||
name=label,
|
||||
)
|
||||
tasks.append(task)
|
||||
if i < n:
|
||||
log.info("Waiting %.0fs before next reservation...", interval)
|
||||
log.info("Waiting %.0fs before next session...", interval)
|
||||
await asyncio.sleep(interval)
|
||||
|
||||
log.info(
|
||||
"All %d reservations in flight; holding plateau for %.0fs, "
|
||||
"All %d sessions in flight; holding plateau for %.0fs, "
|
||||
"then scaling down %.0fs apart",
|
||||
n,
|
||||
plateau,
|
||||
@@ -106,19 +116,19 @@ def build_arg_parser() -> argparse.ArgumentParser:
|
||||
"--duration",
|
||||
type=float,
|
||||
default=180.0,
|
||||
help="Seconds to hold each worker busy (default: 180)",
|
||||
help="Single-reserve mode: seconds to hold the worker (default: 180)",
|
||||
)
|
||||
|
||||
modes = p.add_mutually_exclusive_group(required=False)
|
||||
modes.add_argument(
|
||||
"--reserve",
|
||||
action="store_true",
|
||||
help="Make a single /reserve call (default if no mode given)",
|
||||
help="Make a single session (default if no mode given)",
|
||||
)
|
||||
modes.add_argument(
|
||||
"--demo",
|
||||
action="store_true",
|
||||
help="Run the staggered 3-reservation demo, cancelling one mid-way",
|
||||
help="Run the staggered 3-reservation trapezoid demo",
|
||||
)
|
||||
|
||||
p.add_argument(
|
||||
@@ -157,15 +167,14 @@ async def main_async():
|
||||
plateau=args.plateau,
|
||||
)
|
||||
else:
|
||||
response = await reserve(
|
||||
await reserve(
|
||||
client,
|
||||
endpoint_name=args.endpoint,
|
||||
duration=args.duration,
|
||||
hold_for=args.duration,
|
||||
label="reservation",
|
||||
)
|
||||
print(f"Reservation result: {response}")
|
||||
except KeyboardInterrupt:
|
||||
log.info("Interrupted; dropping any in-flight reservations")
|
||||
log.info("Interrupted; dropping any in-flight sessions")
|
||||
except Exception as e:
|
||||
log.error("Error: %s", e, exc_info=True)
|
||||
sys.exit(1)
|
||||
|
||||
+70
-121
@@ -2,7 +2,6 @@ import asyncio
|
||||
import logging
|
||||
import os
|
||||
from contextlib import asynccontextmanager
|
||||
from typing import Optional
|
||||
from urllib.parse import urlsplit
|
||||
|
||||
from aiohttp import web
|
||||
@@ -17,21 +16,21 @@ from vastai import (
|
||||
|
||||
log = logging.getLogger(__file__)
|
||||
|
||||
# Safety cap: if the user's queue consumer never calls /release, the
|
||||
# reservation is auto-released after this many seconds so a forgotten /release
|
||||
# can't pin a worker indefinitely. Override with MAX_RESERVATION_SECONDS.
|
||||
MAX_RESERVATION_SECONDS = float(os.environ.get("MAX_RESERVATION_SECONDS", 3600))
|
||||
# Performance value pinned in the benchmark cache; sent to autoscaler as
|
||||
# max_perf. Standardized at 100 — the conventional default the rest of the
|
||||
# serverless system expects.
|
||||
TARGET_PERF = 100.0
|
||||
|
||||
# Marker the benchmark path sets so the same remote function can return
|
||||
# immediately during capacity estimation instead of sleeping.
|
||||
# Marker the benchmark path sets so the fallback /ping path returns
|
||||
# immediately during the framework's startup benchmark.
|
||||
BENCHMARK_SENTINEL = "__null_worker_benchmark__"
|
||||
|
||||
# Internal control server. Hosts:
|
||||
# * POST /release — always available, marks the active reservation as
|
||||
# done so the held /reserve returns 200 (success in metrics, not a
|
||||
# cancellation).
|
||||
# * GET /health — only when no external BACKEND_HEALTH_URL is set; the
|
||||
# framework's healthcheck loop polls it so the worker has a live signal.
|
||||
# * POST /release — releases the active reservation by closing the
|
||||
# singleton session on this worker. Called by the user's queue
|
||||
# consumer when its work is done.
|
||||
# * GET /health — only when BACKEND_HEALTH_URL is unset; gives the
|
||||
# framework's healthcheck loop something live to talk to.
|
||||
# Bound to 127.0.0.1 so only processes on the instance can reach it.
|
||||
INTERNAL_HOST = "127.0.0.1"
|
||||
INTERNAL_PORT = int(os.environ.get("NULL_CONTROL_PORT", 18999))
|
||||
@@ -56,62 +55,51 @@ else:
|
||||
USE_STUB_HEALTH = True
|
||||
|
||||
|
||||
# Workload reported per /reserve and target perf for the heartbeat below.
|
||||
TARGET_PERF = 150.0
|
||||
|
||||
# Singleton active reservation. `allow_parallel_requests=False` on the
|
||||
# /reserve handler guarantees the framework only runs one at a time per
|
||||
# worker, so a single slot is enough.
|
||||
_active_reservation: Optional[asyncio.Event] = None
|
||||
|
||||
# Backed in after Worker(...) is constructed so the heartbeat coroutine in
|
||||
# null_lifecycle() can mutate backend.metrics. Stored in a dict so the
|
||||
# lifecycle closure picks up the assignment that happens before .run().
|
||||
# Stashed after Worker(...) is constructed so /release can reach the
|
||||
# framework's session machinery. Dict so the lifecycle closure picks up
|
||||
# the assignment that happens before .run().
|
||||
_backend_ref: dict = {"backend": None}
|
||||
|
||||
|
||||
async def _perf_heartbeat() -> None:
|
||||
"""Keep cur_perf pegged to TARGET_PERF while a reservation is held.
|
||||
|
||||
Without this, workload_served stays at 0 while a /reserve is being held
|
||||
open. The autoscaler observes cur_perf=0 against max_perf=150, decides
|
||||
the worker can't deliver its claimed throughput, and downgrades it —
|
||||
which makes it cautious about scaling up and prone to queueing
|
||||
subsequent requests behind the held one instead of routing elsewhere.
|
||||
|
||||
Every second, if anything is in flight, set workload_served=TARGET_PERF
|
||||
and mark update_pending so the metrics loop sends immediately. The
|
||||
metrics tick resets workload_served back to 0 after sending; we
|
||||
re-pin it next iteration.
|
||||
"""
|
||||
while True:
|
||||
try:
|
||||
await asyncio.sleep(1.0)
|
||||
backend = _backend_ref.get("backend")
|
||||
if backend is None:
|
||||
continue
|
||||
mm = backend.metrics.model_metrics
|
||||
if mm.requests_working:
|
||||
mm.workload_served = TARGET_PERF
|
||||
backend.metrics.update_pending = True
|
||||
except asyncio.CancelledError:
|
||||
raise
|
||||
except Exception as e:
|
||||
log.debug(f"perf heartbeat error: {e}")
|
||||
|
||||
|
||||
def _build_internal_app() -> web.Application:
|
||||
app = web.Application()
|
||||
|
||||
async def release_handler(_request: web.Request) -> web.Response:
|
||||
event = _active_reservation
|
||||
if event is None:
|
||||
"""End the active reservation (the singleton session on this worker).
|
||||
|
||||
max_sessions=1 means at most one session is active here. We call
|
||||
the framework's internal __close_session via name-mangling to
|
||||
bypass the session_auth check that /session/end normally requires.
|
||||
That's intentional: this endpoint is localhost-only so trust is
|
||||
assumed, and the user's consumer can release without having to
|
||||
plumb session_auth through their queue.
|
||||
|
||||
__close_session reports the session metrics as a success, fires
|
||||
on_close_route if configured, and pops the session from the dict.
|
||||
"""
|
||||
backend = _backend_ref.get("backend")
|
||||
if backend is None:
|
||||
return web.json_response(
|
||||
{"released": False, "reason": "no active reservation"},
|
||||
{"released": False, "reason": "backend not ready"},
|
||||
status=503,
|
||||
)
|
||||
sids = list(backend.sessions.keys())
|
||||
if not sids:
|
||||
return web.json_response(
|
||||
{"released": False, "reason": "no active session"},
|
||||
status=200,
|
||||
)
|
||||
closed = []
|
||||
for sid in sids:
|
||||
try:
|
||||
if await backend._Backend__close_session(sid):
|
||||
closed.append(sid)
|
||||
except Exception as e:
|
||||
log.warning(f"Error closing session {sid}: {e}")
|
||||
return web.json_response(
|
||||
{"released": bool(closed), "session_ids": closed},
|
||||
status=200,
|
||||
)
|
||||
event.set()
|
||||
return web.json_response({"released": True}, status=200)
|
||||
|
||||
app.router.add_post("/release", release_handler)
|
||||
|
||||
@@ -126,18 +114,14 @@ def _build_internal_app() -> web.Application:
|
||||
|
||||
@asynccontextmanager
|
||||
async def null_lifecycle():
|
||||
# Pin max_throughput to exactly 100 by pre-populating the framework's
|
||||
# benchmark cache file. The framework's __run_benchmark short-circuits
|
||||
# to `float(file_contents)` when this file exists, bypassing the
|
||||
# time-based calculation that would otherwise drift to ~99.x due to
|
||||
# asyncio scheduling overhead. The filename matches the framework
|
||||
# constant BENCHMARK_INDICATOR_FILE in
|
||||
# vastai.serverless.server.lib.backend.
|
||||
# Pin max_throughput to exactly TARGET_PERF by pre-populating the
|
||||
# framework's benchmark cache file. __run_benchmark short-circuits to
|
||||
# float(file_contents) when this file exists.
|
||||
try:
|
||||
with open(".has_benchmark", "w") as fh:
|
||||
fh.write("150")
|
||||
fh.write(str(int(TARGET_PERF)))
|
||||
except OSError as e:
|
||||
log.warning(f"Could not pin benchmark cache to 150: {e}")
|
||||
log.warning(f"Could not pin benchmark cache: {e}")
|
||||
|
||||
app = _build_internal_app()
|
||||
runner = web.AppRunner(app)
|
||||
@@ -145,8 +129,6 @@ async def null_lifecycle():
|
||||
site = web.TCPSite(runner, INTERNAL_HOST, INTERNAL_PORT)
|
||||
await site.start()
|
||||
|
||||
heartbeat = asyncio.create_task(_perf_heartbeat(), name="null-perf-heartbeat")
|
||||
|
||||
lines = [
|
||||
f"Null pyworker internal control server: http://{INTERNAL_HOST}:{INTERNAL_PORT}",
|
||||
f" POST /release - end the active reservation (call from your queue consumer)",
|
||||
@@ -157,60 +139,32 @@ async def null_lifecycle():
|
||||
)
|
||||
else:
|
||||
lines.append(f"Framework healthcheck pointed at: {BACKEND_HEALTH_URL}")
|
||||
lines.append(
|
||||
"Reservations use the framework session model. Clients POST to "
|
||||
"/session/create via the SDK to acquire a worker; max_sessions=1 "
|
||||
"so each worker holds at most one reservation."
|
||||
)
|
||||
log.info("\n".join(lines))
|
||||
|
||||
try:
|
||||
yield
|
||||
finally:
|
||||
heartbeat.cancel()
|
||||
try:
|
||||
await heartbeat
|
||||
except (asyncio.CancelledError, Exception):
|
||||
pass
|
||||
await runner.cleanup()
|
||||
|
||||
|
||||
async def reserve_worker(**params: object) -> dict:
|
||||
global _active_reservation
|
||||
|
||||
async def ping(**params: object) -> dict:
|
||||
"""Trivial handler. Exists to satisfy the framework's requirement that
|
||||
at least one HandlerConfig has a BenchmarkConfig, and to give clients
|
||||
a route they can hit with session_id to extend their session TTL.
|
||||
"""
|
||||
if params.get(BENCHMARK_SENTINEL):
|
||||
# Fallback path only — the lifecycle pre-populates .has_benchmark
|
||||
# with "150" so __run_benchmark normally short-circuits and never
|
||||
# invokes us. If the cache write failed, sleep ~1s so the
|
||||
# time-based calculation lands near 150 (workload=150 / time~=1s).
|
||||
# Fallback only — the lifecycle pre-pins .has_benchmark so
|
||||
# __run_benchmark normally short-circuits and this never runs. If
|
||||
# the cache write failed, sleep ~1s so the time-based throughput
|
||||
# math lands near TARGET_PERF.
|
||||
await asyncio.sleep(1.0)
|
||||
return {"ok": True, "benchmark": True}
|
||||
|
||||
requested = params.get("duration")
|
||||
if requested is None:
|
||||
duration = MAX_RESERVATION_SECONDS
|
||||
else:
|
||||
try:
|
||||
duration = max(0.0, min(float(requested), MAX_RESERVATION_SECONDS))
|
||||
except (TypeError, ValueError):
|
||||
duration = MAX_RESERVATION_SECONDS
|
||||
|
||||
event = asyncio.Event()
|
||||
_active_reservation = event
|
||||
log.info(
|
||||
f"Reservation acquired; awaiting POST /release on "
|
||||
f"http://{INTERNAL_HOST}:{INTERNAL_PORT}/release "
|
||||
f"(auto-release after {duration:.1f}s)"
|
||||
)
|
||||
try:
|
||||
try:
|
||||
await asyncio.wait_for(event.wait(), timeout=duration)
|
||||
log.info("Reservation released via /release")
|
||||
return {"released": "explicit", "duration_cap": duration}
|
||||
except asyncio.TimeoutError:
|
||||
log.warning(
|
||||
f"Reservation hit duration cap of {duration:.1f}s without "
|
||||
f"explicit /release; releasing automatically"
|
||||
)
|
||||
return {"released": "duration_elapsed", "duration": duration}
|
||||
finally:
|
||||
if _active_reservation is event:
|
||||
_active_reservation = None
|
||||
return {"ok": True}
|
||||
|
||||
|
||||
worker_config = WorkerConfig(
|
||||
@@ -218,17 +172,12 @@ worker_config = WorkerConfig(
|
||||
model_server_port=HEALTH_PORT,
|
||||
model_healthcheck_url=HEALTH_PATH,
|
||||
lifecycle=null_lifecycle(),
|
||||
max_sessions=1,
|
||||
handlers=[
|
||||
HandlerConfig(
|
||||
route="/reserve",
|
||||
allow_parallel_requests=False,
|
||||
# Reject (429) any /reserve that arrives while the worker is
|
||||
# already busy. A held reservation lasts up to MAX_RESERVATION_
|
||||
# SECONDS, so queueing behind it would mean hours of wait —
|
||||
# better to bounce the request immediately so serverless routes
|
||||
# it to a free worker (or spins up a new one).
|
||||
max_queue_time=0.0,
|
||||
remote_function=reserve_worker,
|
||||
route="/ping",
|
||||
allow_parallel_requests=True,
|
||||
remote_function=ping,
|
||||
workload_calculator=lambda _payload: TARGET_PERF,
|
||||
benchmark_config=BenchmarkConfig(
|
||||
generator=lambda: {BENCHMARK_SENTINEL: True},
|
||||
|
||||
Reference in New Issue
Block a user