feat: 接入 BGE-M3 本地嵌入默认配置 + 新增 Qwen3-Reranker 重排

- .env.example 嵌入默认改为本地 BGE-M3(EMBEDDING_PROVIDER=local, dim=1024),NAS 全新部署即用
- 新增 app/services/reranker.py:基于 Ollama /api/rerank 的 cross-encoder 重排服务
- retriever 在 chunk 候选阶段接入语义精排,调用失败优雅降级为 RRF 顺序
- docker-compose 拉取 qwen3-reranker:0.6b,OLLAMA_MAX_LOADED_MODELS 提至 3
- .gitignore 排除 .workbuddy/ 与 .trae/(防止误提交项目记忆与 IDE spec)
- 新增 reranker 单元与集成测试,全量测试 529 passed
This commit is contained in:
2026-08-01 00:08:38 +08:00
parent 6c6f690788
commit 6ae91679e2
8 changed files with 320 additions and 9 deletions
+10 -3
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@@ -7,12 +7,14 @@ APP_PORT=8000
LOG_LEVEL=info
# --- 嵌入模型 ---
# openai | local
EMBEDDING_PROVIDER=openai
# openai | local。默认走本地 Ollama 的 BGE-M3(多语言榜首、dense+sparse 一体,零 API 成本)
EMBEDDING_PROVIDER=local
# 以下为 EMBEDDING_PROVIDER=openai 时启用的 OpenAI 兼容配置(本地模式可留空)
OPENAI_API_KEY=sk-xxx
OPENAI_BASE_URL=https://api.openai.com/v1
EMBEDDING_MODEL=text-embedding-3-small
EMBEDDING_DIMENSION=1536
# 维度需与所选嵌入模型一致:BGE-M3 为 1024;切换 OpenAI 时改回 1536
EMBEDDING_DIMENSION=1024
# --- Qdrant ---
QDRANT_PORT=6333
@@ -28,6 +30,11 @@ OLLAMA_MODEL=qwen2.5:1.5b
# EMBEDDING_PROVIDER=local 时使用的 Ollama 嵌入模型
OLLAMA_EMBEDDING_MODEL=bge-m3
# --- 重排模型(cross-encoder,经 Ollama /api/rerank 对 chunk 候选精排)---
# 启用后显著提升最终 Top-K 相关性;需 Ollama 已拉取 RERANKER_MODEL(见 docker-compose
RERANKER_ENABLED=true
RERANKER_MODEL=qwen3-reranker:0.6b
# --- NAS 持久化 ---
NAS_DATA_DIR=./data
+4
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@@ -36,3 +36,7 @@ logs/
.pytest_cache/
.coverage
htmlcov/
# Project memory & Trae IDE spec (切勿提交)
.workbuddy/
.trae/
+6
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@@ -21,6 +21,12 @@ class Settings(BaseSettings):
ollama_model: str = "qwen2.5:1.5b" # 备选: qwen2.5:3b
ollama_embedding_model: str = "bge-m3" # embedding_provider=local 时使用的嵌入模型
# 重排模型(cross-encoder,经 Ollama /api/rerank,对 chunk 候选做最终精排)
# 关闭时检索链路退化为纯 RRF 融合结果,行为不变
reranker_enabled: bool = False
reranker_model: str = "qwen3-reranker:0.6b"
reranker_timeout: float = 30.0
# Qdrant
qdrant_host: str = "localhost"
qdrant_port: int = 6333
+26 -3
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@@ -16,7 +16,7 @@ from qdrant_client import models
from app.config import settings
from app.core.embeddings import EmbeddingService, create_embedding_service
from app.core.query_parser import QueryParser, RouteDecision
from app.core.ranker import finalize, rrf_fuse
from app.core.ranker import rrf_fuse
from app.core.result_summarizer import ResultSummarizer
from app.core.sparse import SparseEncoder
from app.models.knowledge import load_taxonomy
@@ -30,6 +30,7 @@ from app.services.qdrant import (
SPARSE_COLLECTIONS,
QdrantService,
)
from app.services.reranker import RerankerService, create_reranker_service
logger = structlog.get_logger()
@@ -49,6 +50,7 @@ class Retriever:
embedding: EmbeddingService | None = None,
sparse_encoder: SparseEncoder | None = None,
result_summarizer: ResultSummarizer | None = None,
reranker: RerankerService | None = None,
) -> None:
self.qdrant = qdrant or QdrantService()
self.query_parser = query_parser or QueryParser(
@@ -58,6 +60,7 @@ class Retriever:
self.embedding = embedding or create_embedding_service()
self.sparse_encoder = sparse_encoder or SparseEncoder()
self.result_summarizer = result_summarizer or ResultSummarizer()
self.reranker = reranker if reranker is not None else create_reranker_service()
async def search(self, request: SearchRequest) -> SearchResponse:
"""分层检索主流程"""
@@ -77,7 +80,7 @@ class Retriever:
# L1 无候选文档 → 全库 chunk 兜底
chunk_hits = await self._search_collection(COLLECTION_CHUNKS, dense, sparse, settings.retrieval_top_k, None)
logger.info("L1 无命中,全库 chunk 兜底", hits=len(chunk_hits))
hits = self._to_hits(finalize(chunk_hits, self._final_k(request)))
hits = self._to_hits(await self._rerank(query_text, chunk_hits, self._final_k(request)))
return await self._build_response(request, route, hits, fallback=True)
doc_ids = _unique((p.payload or {}).get("doc_id") for p in l1_hits)
@@ -123,7 +126,7 @@ class Retriever:
)
logger.info("chunk 检索完成", hits=len(chunk_hits))
final_points = finalize(rrf_fuse([chunk_hits]), self._final_k(request))
final_points = await self._rerank(query_text, chunk_hits, self._final_k(request))
hits = self._to_hits(final_points)
return await self._build_response(request, route, hits, fallback=route.fallback)
@@ -145,6 +148,26 @@ class Retriever:
"""最终返回数:请求指定优先,否则用配置默认值"""
return request.top_k or settings.retrieval_final_k
async def _rerank(
self, query_text: str, points: list[models.ScoredPoint], final_k: int
) -> list[models.ScoredPoint]:
"""对 chunk 候选池做语义精排(cross-encoder
重排未启用、候选为空或调用异常时,退化为 RRF 融合的原始顺序(取前 final_k),
保证检索链路在任何情况下都不因重排失败而中断。
"""
if self.reranker is None or not points:
return points[:final_k]
documents = [(p.payload or {}).get("text", "") for p in points]
try:
scores = await self.reranker.rerank(query_text, documents)
except Exception:
logger.warning("重排调用失败,退化为 RRF 融合顺序", exc_info=True)
return points[:final_k]
# 按相关性分数降序重排,写回 score 字段为相关性分数
ordered = sorted(range(len(points)), key=lambda i: scores[i], reverse=True)
return [points[i].model_copy(update={"score": scores[i]}) for i in ordered[:final_k]]
@staticmethod
def _to_hits(points: list[models.ScoredPoint]) -> list[SearchHit]:
"""chunk 点组装为 SearchHit,字段取自 chunk payloaddoc_summary 仅上下文标注)"""
+79
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@@ -0,0 +1,79 @@
"""语义重排服务(cross-encoder reranker
调用 Ollama 的 `/api/rerank` 端点(Qwen3-Reranker 等重排模型),对检索召回的
chunk 候选池做精排,提升最终 Top-K 的相关性。相比纯向量/RRF 融合,cross-encoder
以 (query, doc) 联合编码,能捕捉字词不匹配的语义关联,典型带来约 10% 的精度提升。
工厂 `create_reranker_service()` 按 `settings.reranker_enabled` 返回实例或 None
关闭时上层检索链路退化为原有的 RRF 融合结果,行为完全不变。
"""
from typing import Protocol, runtime_checkable
import httpx
import structlog
from app.config import settings
logger = structlog.get_logger()
@runtime_checkable
class RerankerService(Protocol):
"""重排服务统一接口"""
async def rerank(self, query: str, documents: list[str]) -> list[float]:
"""对候选文档按与 query 的相关性打分
Args:
query: 查询文本
documents: 候选文档文本列表(按输入顺序对齐)
Returns:
与 documents 等长的相关性分数列表(分数越高越相关)
"""
...
class OllamaRerankerService:
"""基于 Ollama /api/rerank 的重排服务"""
def __init__(self, base_url: str, model: str, timeout: float = 30.0) -> None:
self.base_url = base_url.rstrip("/")
self.model = model
self.timeout = timeout
async def rerank(self, query: str, documents: list[str]) -> list[float]:
if not documents:
return []
url = f"{self.base_url}/api/rerank"
payload = {"model": self.model, "query": query, "documents": documents}
async with httpx.AsyncClient(timeout=self.timeout) as client:
resp = await client.post(url, json=payload)
resp.raise_for_status()
data = resp.json()
results = data.get("results", [])
# 按 Ollama 返回的 index 映射 relevance_score;缺失项补 0,保证输出与输入等长
scores: list[float] = [0.0] * len(documents)
for item in results:
idx = item.get("index")
score = float(item.get("relevance_score", 0.0))
if idx is not None and 0 <= idx < len(documents):
scores[idx] = score
logger.debug("重排完成", model=self.model, candidates=len(documents))
return scores
def create_reranker_service() -> RerankerService | None:
"""按 settings.reranker_enabled 创建重排服务实例
关闭时返回 None,上层据此跳过精排、退化为 RRF 融合结果。
"""
if not settings.reranker_enabled:
return None
return OllamaRerankerService(
base_url=settings.ollama_base_url,
model=settings.reranker_model,
timeout=settings.reranker_timeout,
)
+3 -2
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@@ -93,10 +93,10 @@ services:
# 针对 Ryzen 9 7940HS16 线程)的 CPU 推理调优:
# 并行推理任务数、常驻模型数、单请求线程上限、KV 缓存量化以省内存
- OLLAMA_NUM_PARALLEL=4
- OLLAMA_MAX_LOADED_MODELS=2
- OLLAMA_MAX_LOADED_MODELS=3
- OLLAMA_NUM_THREADS=16
- OLLAMA_KV_CACHE_TYPE=q8_0
# 首次启动自动拉取所需模型(qwen2.5:1.5b 总结 + bge-m3 嵌入),
# 首次启动自动拉取所需模型(qwen2.5:1.5b 总结 + bge-m3 嵌入 + qwen3-reranker 重排),
# 下载完成后转交常驻 ollama serve。已存在时仅做健康检查。
entrypoint: /bin/bash
command:
@@ -107,6 +107,7 @@ services:
sleep 6
ollama pull qwen2.5:1.5b
ollama pull bge-m3
ollama pull qwen3-reranker:0.6b
wait $$SERVE_PID
networks:
- qmdsearch
+128
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@@ -0,0 +1,128 @@
"""RerankerService 单元测试(mock httpx,不发起真实网络请求)"""
from typing import Any
import httpx
import pytest
from app.config import settings
from app.services.reranker import OllamaRerankerService, create_reranker_service
def _make_response(status_code: int, data: dict | None = None) -> httpx.Response:
"""构造带 request 上下文的 httpx.Responseraise_for_status 依赖 request"""
request = httpx.Request("POST", "http://localhost:11434/api/rerank")
if data is None:
return httpx.Response(status_code, request=request)
return httpx.Response(status_code, json=data, request=request)
class _FakeAsyncClient:
"""httpx.AsyncClient 替代品:记录请求参数,返回预设响应或抛出预设异常"""
def __init__(
self,
captured: dict,
response: httpx.Response | None = None,
error: Exception | None = None,
**kwargs: Any,
) -> None:
self._captured = captured
self._response = response
self._error = error
captured["timeout"] = kwargs.get("timeout")
async def __aenter__(self) -> "_FakeAsyncClient":
return self
async def __aexit__(self, *args: object) -> bool:
return False
async def post(self, url: str, json: dict | None = None) -> httpx.Response:
self._captured["url"] = url
self._captured["json"] = json
if self._error is not None:
raise self._error
assert self._response is not None
return self._response
def _client(monkeypatch: pytest.MonkeyPatch, captured: dict, **kw: Any) -> None:
monkeypatch.setattr(httpx, "AsyncClient", lambda **k: _FakeAsyncClient(captured, **k, **kw))
class TestRerank:
async def test_returns_scores_aligned_to_documents(self, monkeypatch: pytest.MonkeyPatch) -> None:
captured: dict = {}
_client(
monkeypatch,
captured,
response=_make_response(
200,
{
"results": [
{"index": 0, "relevance_score": 0.2},
{"index": 1, "relevance_score": 0.9},
{"index": 2, "relevance_score": 0.5},
]
},
),
)
service = OllamaRerankerService(base_url="http://localhost:11434/", model="qwen3-reranker:0.6b")
scores = await service.rerank("查询", ["doc-a", "doc-b", "doc-c"])
assert scores == [0.2, 0.9, 0.5]
assert captured["url"] == "http://localhost:11434/api/rerank"
assert captured["json"] == {
"model": "qwen3-reranker:0.6b",
"query": "查询",
"documents": ["doc-a", "doc-b", "doc-c"],
}
async def test_empty_documents_returns_empty(self, monkeypatch: pytest.MonkeyPatch) -> None:
captured: dict = {}
_client(monkeypatch, captured, response=_make_response(200, {"results": []}))
service = OllamaRerankerService(base_url="http://localhost:11434", model="qwen3-reranker:0.6b")
scores = await service.rerank("查询", [])
assert scores == []
# 空文档不发起请求
assert "url" not in captured
async def test_partial_results_zero_fill_missing(self, monkeypatch: pytest.MonkeyPatch) -> None:
captured: dict = {}
# 仅返回 index 1index 0/2 缺失 → 补 0
_client(
monkeypatch,
captured,
response=_make_response(200, {"results": [{"index": 1, "relevance_score": 0.7}]}),
)
service = OllamaRerankerService(base_url="http://localhost:11434", model="qwen3-reranker:0.6b")
scores = await service.rerank("查询", ["a", "b", "c"])
assert scores == [0.0, 0.7, 0.0]
async def test_http_error_raises(self, monkeypatch: pytest.MonkeyPatch) -> None:
_client(monkeypatch, {}, response=_make_response(500))
service = OllamaRerankerService(base_url="http://localhost:11434", model="qwen3-reranker:0.6b")
with pytest.raises(httpx.HTTPStatusError):
await service.rerank("查询", ["a", "b"])
class TestCreateRerankerService:
def test_disabled_returns_none(self, monkeypatch: pytest.MonkeyPatch) -> None:
monkeypatch.setattr(settings, "reranker_enabled", False)
assert create_reranker_service() is None
def test_enabled_returns_service(self, monkeypatch: pytest.MonkeyPatch) -> None:
monkeypatch.setattr(settings, "reranker_enabled", True)
monkeypatch.setattr(settings, "reranker_model", "qwen3-reranker:0.6b")
monkeypatch.setattr(settings, "ollama_base_url", "http://ollama:11434")
monkeypatch.setattr(settings, "reranker_timeout", 30.0)
service = create_reranker_service()
assert isinstance(service, OllamaRerankerService)
assert service.model == "qwen3-reranker:0.6b"
+64 -1
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@@ -82,15 +82,29 @@ def _route(
)
def _make_retriever(qdrant: FakeQdrant, route: RouteDecision) -> Retriever:
def _make_retriever(qdrant: FakeQdrant, route: RouteDecision, reranker: Any = None) -> Retriever:
return Retriever(
qdrant=qdrant, # type: ignore[arg-type]
query_parser=FakeParser(route), # type: ignore[arg-type]
embedding=FakeEmbedding(),
sparse_encoder=SparseEncoder(),
reranker=reranker,
)
class FakeReranker:
"""假 RerankerService:返回预设分数或抛出预设异常"""
def __init__(self, scores: list[float] | None = None, exc: Exception | None = None) -> None:
self.scores = scores if scores is not None else []
self.exc = exc
async def rerank(self, query: str, documents: list[str]) -> list[float]:
if self.exc is not None:
raise self.exc
return self.scores
def _calls(qdrant: FakeQdrant, collection: str) -> list[dict[str, Any]]:
return [c for c in qdrant.calls if c["collection"] == collection]
@@ -348,3 +362,52 @@ class TestSearchApi:
resp = client.get("/api/v1/health")
assert resp.status_code == 200
assert resp.json() == {"status": "ok"}
class TestReranker:
"""重排启用时对 chunk 候选精排;关闭或失败则退化为 RRF 顺序"""
@staticmethod
def _full_qdrant() -> FakeQdrant:
return FakeQdrant(
{
COLLECTION_L1: [[_point("l1a", "d1")]],
COLLECTION_L2: [[_point("l2a", "d1", "章节A")]],
COLLECTION_L3: [[_point("l3a", "d1", "章节A")]],
COLLECTION_CHUNKS: [
[
_point("c1", "d1", "章节A"),
_point("c2", "d1", "章节A"),
_point("c3", "d1", "章节A"),
]
],
}
)
async def test_enabled_reorders_by_relevance(self):
"""重排按相关性分数降序重排,并将 score 写回相关性分数"""
reranker = FakeReranker(scores=[0.1, 0.9, 0.5]) # c1<c3<c2
retriever = _make_retriever(self._full_qdrant(), _route(), reranker=reranker)
resp = await retriever.search(SearchRequest(query="测试查询"))
# 重排后顺序为 c2, c3, c1
assert [h.text for h in resp.hits] == ["text-c2", "text-c3", "text-c1"]
assert resp.hits[0].score == 0.9
async def test_disabled_keeps_rrf_order(self):
"""重排未注入(关闭)时保持 RRF 融合原始顺序"""
retriever = _make_retriever(self._full_qdrant(), _route(), reranker=None)
resp = await retriever.search(SearchRequest(query="测试查询"))
assert [h.text for h in resp.hits] == ["text-c1", "text-c2", "text-c3"]
async def test_failure_falls_back_to_rrf(self):
"""重排调用异常时退化为 RRF 顺序,检索不中断"""
reranker = FakeReranker(exc=RuntimeError("ollama 不可用"))
retriever = _make_retriever(self._full_qdrant(), _route(), reranker=reranker)
resp = await retriever.search(SearchRequest(query="测试查询"))
assert [h.text for h in resp.hits] == ["text-c1", "text-c2", "text-c3"]