Fit FLUX hot swap within 16 GiB VRAM

platform/docker/flux-worker/flux_worker.py

@@ -30,7 +30,15 @@ def load_pipeline() -> None:
     from diffusers import DiffusionPipeline
     started = time.monotonic()
     PIPE = DiffusionPipeline.from_pretrained(
-        MODEL_DIR, torch_dtype=torch.bfloat16, device_map="cuda")
+        MODEL_DIR, torch_dtype=torch.bfloat16)
+    # The full pipeline leaves too little activation headroom on a 16 GiB
+    # RTX 5080. Model CPU offload keeps each active component on CUDA while
+    # parking inactive components in system RAM between the four steps.
+    PIPE.enable_model_cpu_offload()
+    if hasattr(PIPE, "enable_vae_slicing"):
+        PIPE.enable_vae_slicing()
+    if hasattr(PIPE, "enable_vae_tiling"):
+        PIPE.enable_vae_tiling()
     LOAD_SECONDS = time.monotonic() - started
 
 
@@ -98,6 +106,8 @@ class Handler(BaseHTTPRequestHandler):
                 raise ValueError("invalid request size")
             self.reply(200, generate(json.loads(self.rfile.read(length))))
         except Exception as exc:
+            print(f"[flux-worker] generation failed: "
+                  f"{type(exc).__name__}: {str(exc)[:1000]}", flush=True)
             self.reply(400, {"status": "error", "message": str(exc)})
 
 

platform/docker/profile-controller/profile_controller.py

@@ -106,7 +106,9 @@ def set_image_worker(running: bool) -> dict:
                 if status not in (204, 304):
                     raise RuntimeError(f"failed to start image worker: HTTP {status}")
         else:
-            stop_container(item)
+            # CUDA/PyTorch may not react promptly to SIGTERM after an OOM.
+            # Bound recovery time and let Docker issue SIGKILL afterwards.
+            stop_container(item, timeout=20)
         return {"image_worker": "running" if running else "stopped"}
 
 

router/ai_profile_router.py

@@ -719,8 +719,17 @@ class _RemoteWorker:
             headers["Content-Type"] = "application/json"
         req = urllib.request.Request(IMAGE_WORKER_URL + path, data=body,
                                      method=method, headers=headers)
-        with urllib.request.urlopen(req, timeout=timeout) as response:
-            return json.load(response)
+        try:
+            with urllib.request.urlopen(req, timeout=timeout) as response:
+                return json.load(response)
+        except urllib.error.HTTPError as exc:
+            try:
+                message = json.loads(exc.read(4096)).get("message")
+            except Exception:
+                message = None
+            raise RuntimeError(message or f"Bild-Worker HTTP {exc.code}") from exc
+        except (OSError, urllib.error.URLError, TimeoutError) as exc:
+            raise RuntimeError(f"Bild-Worker nicht erreichbar: {exc}") from exc
 
     def start(self) -> None:
         if not IMAGE_WORKER_TOKEN or len(IMAGE_WORKER_TOKEN) < 32: