Files
destengssv006_home/.local/share/pytorch_pod/python-apps/embed-multimodal-7b.py
2025-11-22 19:37:35 +01:00

507 lines
16 KiB
Python
Executable File

#!/usr/bin/env python
import base64
import gc
import io
import os
import threading
from typing import List, Optional
import torch
from colpali_engine.models import ColQwen2_5, ColQwen2_5_Processor
from fastapi import FastAPI, HTTPException
from PIL import Image, ImageFile
from pydantic import BaseModel, Field
from transformers.utils.import_utils import is_flash_attn_2_available
# --------------------------------------------------------------------------------------
# Configuration
# --------------------------------------------------------------------------------------
# Allowed models (strictly limited per user request)
MODEL_ID_NOMIC = "nomic-ai/colnomic-embed-multimodal-7b"
MODEL_ID_EVO_7B = "ApsaraStackMaaS/EvoQwen2.5-VL-Retriever-7B-v1"
ALLOWED_MODEL_IDS = {MODEL_ID_NOMIC, MODEL_ID_EVO_7B}
# Default selected model (must be one of ALLOWED_MODEL_IDS). If env not allowed, fallback to MODEL_ID_NOMIC.
ENV_DEFAULT_MODEL = os.environ.get("HF_MODEL_ID", MODEL_ID_NOMIC)
DEFAULT_MODEL_ID = (
ENV_DEFAULT_MODEL if ENV_DEFAULT_MODEL in ALLOWED_MODEL_IDS else MODEL_ID_NOMIC
)
HF_MODEL_URL = os.environ.get("HF_MODEL_URL") # optional informational field
API_PORT = int(os.environ.get("PYTORCH_CONTAINER_PORT", os.environ.get("PORT", "8000")))
# Limits (env-overridable)
MAX_TEXTS_PER_REQUEST = int(os.environ.get("TEXT_MAX_ITEMS", "32"))
MAX_IMAGES_PER_REQUEST = int(os.environ.get("IMAGE_MAX_ITEMS", "8"))
MAX_IMAGE_BASE64_BYTES = int(
os.environ.get("IMAGE_MAX_BASE64_BYTES", str(25 * 1024 * 1024))
) # 25MB per image b64 (approx)
MAX_IMAGE_PIXELS = int(
os.environ.get("IMAGE_MAX_PIXELS", str(30_000_000))
) # ~30MP safety
# PIL safety for large images
ImageFile.LOAD_TRUNCATED_IMAGES = True
Image.MAX_IMAGE_PIXELS = MAX_IMAGE_PIXELS
# --------------------------------------------------------------------------------------
# App + Global State
# --------------------------------------------------------------------------------------
app = FastAPI(title="Colnomic Embed Multimodal API")
_model_lock = threading.RLock()
_model: Optional[torch.nn.Module] = None
_processor: Optional[ColQwen2_5_Processor] = None
_loaded_model_id: Optional[str] = None
# For reporting
_dtype_str: Optional[str] = None
_device_str: str = "cuda:0"
_active_model_id: str = DEFAULT_MODEL_ID
# --------------------------------------------------------------------------------------
# Pydantic Models
# --------------------------------------------------------------------------------------
class SelectModelRequest(BaseModel):
model_id: str = Field(..., description="One of the allowed model IDs")
class EmbedTextsRequest(BaseModel):
# Validated in handler for min length
texts: List[str]
class EmbedResponse(BaseModel):
model_id: str
# results[batch][tokens][dim]
results: List[List[List[float]]]
class EmbedImagesRequest(BaseModel):
# Validated in handler for min length
images_b64: List[str] # base64 encoded images only
class ImageMetadata(BaseModel):
index: int
status: str # "ok" | "error"
width: Optional[int] = None
height: Optional[int] = None
mode: Optional[str] = None
error: Optional[str] = None
class EmbedImagesResponse(BaseModel):
model_id: str
results: List[List[List[float]]]
metadata: List[ImageMetadata]
# --------------------------------------------------------------------------------------
# Helpers
# --------------------------------------------------------------------------------------
def _torch_dtype_str(dtype: torch.dtype) -> str:
if dtype == torch.bfloat16:
return "bfloat16"
if dtype == torch.float16:
return "float16"
return str(dtype)
def _hard_requirements_check():
# CUDA hard requirement
if not torch.cuda.is_available():
raise RuntimeError("CUDA is not available; a CUDA-capable GPU is required.")
# FlashAttention-2 hard requirement
if not is_flash_attn_2_available():
raise RuntimeError(
"flash_attn_2 is not available; this deployment requires FlashAttention-2."
)
def _pick_dtype() -> torch.dtype:
return torch.bfloat16 if torch.cuda.is_bf16_supported() else torch.float16
def _unload_model_locked():
global _model, _processor, _loaded_model_id, _dtype_str
# Assumes caller holds _model_lock
before_free, before_total = (0, 0)
if torch.cuda.is_available():
free, total = torch.cuda.mem_get_info(0)
before_free, before_total = free, total
_model = None
_processor = None
_loaded_model_id = None
_dtype_str = None
gc.collect()
if torch.cuda.is_available():
try:
torch.cuda.empty_cache()
torch.cuda.ipc_collect()
except Exception:
# Best-effort cleanup; continue
pass
after_free, after_total = (0, 0)
if torch.cuda.is_available():
free, total = torch.cuda.mem_get_info(0)
after_free, after_total = free, total
return {
"before": {"free": before_free, "total": before_total},
"after": {"free": after_free, "total": after_total},
"freed": max(0, (after_free - before_free)),
}
def _load_model_locked(model_id: str):
# Assumes caller holds _model_lock
global _model, _processor, _loaded_model_id, _dtype_str, _device_str
_hard_requirements_check()
dtype = _pick_dtype()
device_map = "cuda:0"
attn_impl = "flash_attention_2" # we ensured availability above
model = ColQwen2_5.from_pretrained(
model_id,
torch_dtype=dtype,
device_map=device_map,
attn_implementation=attn_impl,
).eval()
processor = ColQwen2_5_Processor.from_pretrained(model_id)
_model = model
_processor = processor
_loaded_model_id = model_id
_dtype_str = _torch_dtype_str(dtype)
_device_str = device_map
def _ensure_model_loaded():
with _model_lock:
if (
_model is not None
and _processor is not None
and _loaded_model_id == _active_model_id
):
model, processor = _model, _processor
assert model is not None and processor is not None
return model, processor
# Different or missing model: (re)load
_unload_model_locked()
_load_model_locked(_active_model_id)
model, processor = _model, _processor
assert model is not None and processor is not None
return model, processor
def _current_vram_info():
if not torch.cuda.is_available():
return {"free": None, "total": None, "used": None}
free, total = torch.cuda.mem_get_info(0)
used = total - free
return {"free": free, "total": total, "used": used}
def _decode_base64_image(b64_data: str):
# Size guard
approx_bytes = int(len(b64_data) * 0.75) # rough, base64 overhead ~33%
if approx_bytes > MAX_IMAGE_BASE64_BYTES:
raise ValueError(
f"Image exceeds max base64 size of {MAX_IMAGE_BASE64_BYTES} bytes"
)
try:
raw = base64.b64decode(b64_data, validate=True)
except Exception as e:
raise ValueError(f"Invalid base64: {e}")
try:
img = Image.open(io.BytesIO(raw))
# Convert to RGB for model compatibility
if img.mode != "RGB":
img = img.convert("RGB")
img.load() # ensure data is read
return img
except Exception as e:
raise ValueError(f"Unable to decode image: {e}")
def _extract_embeddings(outputs) -> torch.Tensor:
# ColQwen2.5 returns either:
# - a tensor shaped (batch, tokens, dim), or
# - an object with .last_hidden_state
if isinstance(outputs, torch.Tensor):
embeddings = outputs
elif hasattr(outputs, "last_hidden_state"):
embeddings = outputs.last_hidden_state
else:
raise RuntimeError(f"Unexpected model output type: {type(outputs)}")
if embeddings.dim() == 2: # (tokens, dim) -> single item
embeddings = embeddings.unsqueeze(0)
elif embeddings.dim() != 3:
raise RuntimeError(f"Unexpected embedding shape: {tuple(embeddings.shape)}")
return embeddings
# --------------------------------------------------------------------------------------
# Endpoints
# --------------------------------------------------------------------------------------
@app.get("/health")
def health():
"""
Health check with hard requirements:
- CUDA available
- FlashAttention-2 available
- Lazy-loads the active model once
- Includes dtype, device, and VRAM info
"""
cuda_ok = bool(torch.cuda.is_available())
flash_ok = bool(is_flash_attn_2_available())
info = {
"status": "ok",
"model_id": _active_model_id,
"model_url": HF_MODEL_URL,
"cuda_available": cuda_ok,
"flash_attn_2_available": flash_ok,
"dtype": _dtype_str,
"device": _device_str,
"vram_bytes": _current_vram_info(),
}
# Hard failures
if not cuda_ok:
info["status"] = "error"
info["error"] = "CUDA is not available inside the container."
raise HTTPException(status_code=500, detail=info)
if not flash_ok:
info["status"] = "error"
info["error"] = (
"flash_attn_2 is not available; this deployment requires FlashAttention-2."
)
raise HTTPException(status_code=500, detail=info)
try:
_ensure_model_loaded()
except Exception as exc:
info["status"] = "error"
info["error"] = str(exc)
raise HTTPException(status_code=500, detail=info) from exc
# Ensure final dtype/device populated
info["dtype"] = _dtype_str
info["device"] = _device_str
info["vram_bytes"] = _current_vram_info()
return info
@app.post("/select-model")
def select_model(req: SelectModelRequest):
"""
Switch the active model between the allowed set.
Fully unloads the current model (free VRAM) then loads the new one.
Blocks concurrent requests briefly via a lock.
"""
global _active_model_id
target = req.model_id.strip()
if target not in ALLOWED_MODEL_IDS:
raise HTTPException(
status_code=400,
detail={
"error": "Unsupported model_id",
"allowed": sorted(list(ALLOWED_MODEL_IDS)),
"received": target,
},
)
with _model_lock:
if (
target == _active_model_id
and _model is not None
and _loaded_model_id == target
):
# No-op
return {
"status": "ok",
"model_id": _active_model_id,
"message": "Model unchanged; already active.",
}
# Switch
_active_model_id = target
_unload_model_locked()
try:
_load_model_locked(_active_model_id)
except Exception as exc:
# Attempt to revert to a safe state: no model loaded
_unload_model_locked()
raise HTTPException(
status_code=500,
detail={"error": f"Failed to load model '{target}': {exc}"},
) from exc
return {"status": "ok", "model_id": _active_model_id}
@app.post("/embed-texts", response_model=EmbedResponse)
def embed_texts(request: EmbedTextsRequest):
"""
Compute multi-vector embeddings for a list of texts.
Result shape: results[batch][tokens][dim] (multi-vector per text).
Limits:
- Max texts per request: TEXT_MAX_ITEMS (default 32)
"""
texts = request.texts
if not texts:
raise HTTPException(status_code=400, detail="texts must not be empty")
if len(texts) > MAX_TEXTS_PER_REQUEST:
raise HTTPException(
status_code=400, detail=f"Too many texts; max is {MAX_TEXTS_PER_REQUEST}"
)
with _model_lock:
model, processor = _ensure_model_loaded()
try:
with torch.inference_mode():
batch = processor.process_queries(texts).to(_device_str)
outputs = model(**batch)
embeddings = _extract_embeddings(outputs)
except Exception as exc:
raise HTTPException(
status_code=500, detail=f"Failed to compute text embeddings: {exc}"
) from exc
embeddings = embeddings.detach().cpu().float()
results = embeddings.tolist()
return EmbedResponse(model_id=_active_model_id, results=results)
@app.post("/embed-images", response_model=EmbedImagesResponse)
def embed_images(request: EmbedImagesRequest):
"""
Compute multi-vector embeddings for a list of base64-encoded images.
Returns results aligned with the input order: results[i] is [] if the i-th image failed to decode.
Limits:
- Max images per request: IMAGE_MAX_ITEMS (default 8)
- Max base64 bytes per image: IMAGE_MAX_BASE64_BYTES (default ~25MB)
- Max image pixels (safety): IMAGE_MAX_PIXELS (default ~30MP)
"""
b64_list = request.images_b64
if not b64_list:
raise HTTPException(status_code=400, detail="images_b64 must not be empty")
if len(b64_list) > MAX_IMAGES_PER_REQUEST:
raise HTTPException(
status_code=400, detail=f"Too many images; max is {MAX_IMAGES_PER_REQUEST}"
)
# Decode individually and track metadata
decoded_images: List[Optional[Image.Image]] = [None] * len(b64_list)
metadata: List[ImageMetadata] = []
ok_indices: List[int] = []
for idx, b64_img in enumerate(b64_list):
try:
img = _decode_base64_image(b64_img)
decoded_images[idx] = img
w, h = img.size
metadata.append(
ImageMetadata(index=idx, status="ok", width=w, height=h, mode=img.mode)
)
ok_indices.append(idx)
except Exception as exc:
metadata.append(ImageMetadata(index=idx, status="error", error=str(exc)))
if not ok_indices:
raise HTTPException(
status_code=400,
detail="All provided images failed to decode or were rejected by limits",
)
# Prepare only successful images for batching, but preserve order in output
images_ok: List[Image.Image] = []
for i in ok_indices:
img_i = decoded_images[i]
assert img_i is not None
images_ok.append(img_i)
with _model_lock:
model, processor = _ensure_model_loaded()
try:
with torch.inference_mode():
batch_images = processor.process_images(images_ok).to(_device_str)
outputs = model(**batch_images)
embeddings = _extract_embeddings(outputs)
except Exception as exc:
raise HTTPException(
status_code=500, detail=f"Failed to compute image embeddings: {exc}"
) from exc
embeddings = embeddings.detach().cpu().float().tolist()
# Distribute embeddings back into results aligned with original indices
# For failed entries, place an empty list [].
results: List[List[List[float]]] = [[] for _ in range(len(b64_list))]
for pos, idx in enumerate(ok_indices):
results[idx] = embeddings[pos]
return EmbedImagesResponse(
model_id=_active_model_id, results=results, metadata=metadata
)
@app.post("/free-vram")
def free_vram():
"""
Frees GPU VRAM by unloading the model/processor and emptying CUDA caches.
The active model selection is preserved, but the next request will re-load the model.
"""
with _model_lock:
before = _current_vram_info()
stats = _unload_model_locked()
after = _current_vram_info()
return {
"status": "ok",
"active_model_id": _active_model_id,
"vram_bytes_before": before,
"vram_bytes_after": after,
"free_stats": stats,
}
# --------------------------------------------------------------------------------------
# Entrypoint
# --------------------------------------------------------------------------------------
if __name__ == "__main__":
import uvicorn
uvicorn.run(app, host="0.0.0.0", port=API_PORT)