mram
42e1386811
Backoff now covers all dial-phase errors (refused, timeout, DNS), TLS handshake failures, and 5xx responses with replayable bodies; streamed POSTs are never replayed to avoid duplicate work. First retry of an episode logs at WARN, subsequent attempts at INFO. LOGLEVEL (LOG_LEVEL kept as alias) now defaults to warn: startup logs version plus every setting; INFO adds one line per incoming request and per response with status/duration, ANSI-colored in text mode (bypasses slog's escaping so colors render in docker compose logs); NO_COLOR or LOG_FORMAT=json disables colors.
112 lines
4.9 KiB
Markdown
112 lines
4.9 KiB
Markdown
# gpu-turnstile
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GPU arbitration proxy for Ollama + ComfyUI. One consumer GPU is shared by an
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LLM server (Ollama) and an image generator (ComfyUI); gpu-turnstile sits in
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front of both and guarantees the GPU is always in exactly one of three states:
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`idle`, `llm` (N ≥ 1 Ollama requests in flight), or `image` (exactly one
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ComfyUI job, Ollama models unloaded). See [SPEC.md](SPEC.md) for the full
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design.
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gpu-turnstile listens on the ports the services normally use; the actual
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services run one port higher (Ollama on 11435, ComfyUI on 8189).
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```
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LiteLLM / Open WebUI ──► :11434 ─┐ ┌─► Ollama :11435
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├── gpu-turnstile (1 lock) ──┤
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Open WebUI / n8n ────► :8188 ───┘ └─► ComfyUI :8189
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```
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- LLM endpoints (`/api/generate`, `/api/chat`, `/api/embed`, `/v1/*`) take the
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LLM lock: concurrent requests allowed, but blocked while an image job is
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active or waiting (image priority).
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- `POST /prompt` on the ComfyUI listener takes the image lock: new LLM
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requests block, in-flight LLMs drain, Ollama models are unloaded, the prompt
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is forwarded, and the lock is held until the job finishes and ComfyUI frees
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its VRAM.
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- Everything else (including websockets and all streaming) passes through
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transparently and unbuffered.
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## Configuration
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All configuration is via environment variables; invalid values fail at
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startup.
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| Var | Default | Meaning |
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|---|---|---|
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| `LISTEN_OLLAMA` | `:11434` | Ollama-facing listener |
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| `LISTEN_COMFY` | `:8188` | ComfyUI-facing listener |
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| `OLLAMA_URL` | `http://127.0.0.1:11435` | Ollama upstream |
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| `COMFY_URL` | `http://127.0.0.1:8189` | ComfyUI upstream |
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| `UNLOAD_TIMEOUT` | `60s` | Wait for Ollama to unload before an image job |
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| `JOB_TIMEOUT` | `15m` | Wait for a ComfyUI job to finish |
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| `LLM_WAIT_TIMEOUT` | `10m` | Max lock wait for an LLM request before 503 |
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| `WARM_MODEL` | _(empty)_ | Model to reload after an image job (off by default) |
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| `LOGLEVEL` | `warn` | `info` logs every request (colored arrows in text mode), `debug` adds lock transitions. `LOG_LEVEL` works as an alias |
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| `LOG_FORMAT` | `text` | `json` for structured JSON logs |
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| `UNLOAD_POLL_INTERVAL` | `500ms` | `/api/ps` poll interval while unloading |
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| `HISTORY_POLL_INTERVAL` | `1s` | `/history/<id>` poll interval while a job runs |
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| `PROBE_TIMEOUT` | `5s` | Startup probe of both upstreams |
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| `FREE_TIMEOUT` | `30s` | `POST /free` call after an image job |
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| `WARM_TIMEOUT` | `2m` | Warm-model reload after an image job |
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| `SHUTDOWN_TIMEOUT` | `10s` | Graceful shutdown on SIGINT/SIGTERM |
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| `BACKOFF_INITIAL` | `1s` | First retry wait when an upstream refuses a connection |
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| `BACKOFF_MAX` | `60s` | Cap for the exponential retry backoff |
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| `PROMPT_CAPTURE_LIMIT` | `65536` | Bytes of the `/prompt` response buffered to find `prompt_id` (pass-through is unaffected) |
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## Observability
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- `GET /healthz` (both listeners): `{"state":"idle|llm|image","llm_inflight":N,"image_pending":B}`
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- `GET /metrics` (Ollama listener): Prometheus text format — `gpu_turnstile_state`,
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`gpu_turnstile_llm_inflight`, `gpu_turnstile_image_pending`,
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`gpu_turnstile_image_jobs_total`, `gpu_turnstile_lock_wait_seconds`
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(histogram, `kind="llm|image"`), `gpu_turnstile_unload_seconds`.
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- Logs: startup logs the version and every setting (visible even at the
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default `warn` level). With `LOGLEVEL=info` or `debug`, every request
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logs a `-->` incoming line and a `<--` response line with status and
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duration — ANSI-colored (cyan incoming; green/yellow/red by status
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class) in text mode, which renders in `docker compose logs` on Windows
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Terminal. Set `NO_COLOR` to disable colors.
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## Build and run
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```sh
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go build ./cmd/gpu-turnstile
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./gpu-turnstile
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```
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```sh
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docker build -t gpu-turnstile .
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docker run --rm -p 11434:11434 -p 8188:8188 \
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-e OLLAMA_URL=http://<workstation-ip>:11435 \
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-e COMFY_URL=http://<workstation-ip>:8189 \
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gpu-turnstile
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```
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Releases are built by Gitea Actions (`.gitea/workflows/ci.yml`): every push
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runs `go vet` and `go test -race`, and pushing a semantic-version tag
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`vX.Y.Z` builds and publishes
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`git.rambossek.at/<owner>/gpu-turnstile:vX.Y.Z` (and updates `:latest`).
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No images are built from branches.
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The registry login needs one repository secret (Settings → Actions →
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Secrets): `REGISTRY_TOKEN` — an access token with `write:package` scope.
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The automatic `GITEA_TOKEN` cannot push packages.
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## Development
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```sh
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go vet ./...
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go test -race ./...
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```
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Stdlib only, Go 1.23+. Layout:
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```
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cmd/gpu-turnstile/main.go wiring, config, listeners
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internal/lock/ two-mode lock (LLM readers / image writer, FIFO)
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internal/ollama/ ps / unload / warm client
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internal/comfy/ history poll / free client
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internal/proxy/ handlers for both listeners
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internal/metrics/ Prometheus exposition, no dependencies
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```
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