fix: prevent ExternalReranker from blocking event loop during RAG queries (#20049)

* fix: prevent ExternalReranker from blocking event loop during RAG queries (#120)

Co-authored-by: Tim Baek <tim@openwebui.com>
Co-authored-by: Claude <noreply@anthropic.com>
Fixes #19900

* Merge pull request open-webui#19030 from open-webui/dev (#122)

Co-authored-by: Tim Baek <tim@openwebui.com>
Co-authored-by: Claude <noreply@anthropic.com>
Fixes #19900

---------

Co-authored-by: Tim Baek <tim@openwebui.com>
Co-authored-by: Claude <noreply@anthropic.com>

backend/open_webui/retrieval/models/external.py

@@ -18,10 +18,12 @@ class ExternalReranker(BaseReranker):
         api_key: str,
         url: str = "http://localhost:8080/v1/rerank",
         model: str = "reranker",
+        timeout: Optional[int] = None,
     ):
         self.api_key = api_key
         self.url = url
         self.model = model
+        self.timeout = timeout
 
     def predict(
         self, sentences: List[Tuple[str, str]], user=None
@@ -52,6 +54,7 @@ class ExternalReranker(BaseReranker):
                 f"{self.url}",
                 headers=headers,
                 json=payload,
+                timeout=self.timeout,
             )
 
             r.raise_for_status()