Fix: release pooled DB connection during AI LLM/embedding calls (#12983)

src/paperless_ai/ai_classifier.py

@@ -8,6 +8,7 @@ from documents.models import Document
 from documents.permissions import get_objects_for_user_owner_aware
 from paperless.config import AIConfig
 from paperless_ai.client import AIClient
+from paperless_ai.db import db_connection_released
 from paperless_ai.indexing import query_similar_documents
 from paperless_ai.indexing import truncate_content
 
@@ -146,20 +147,23 @@ def get_ai_document_classification(
     )
 
     client = AIClient()
-    result = client.run_llm_query(prompt)
-    suggestions = parse_ai_response(result)
-    if output_language:
-        localized = client.run_llm_query(
-            build_localization_prompt(suggestions, output_language),
-        )
-        localized_suggestions = parse_ai_response(localized)
-        suggestions = {
-            **suggestions,
-            "title": localized_suggestions["title"] or suggestions["title"],
-            "tags": localized_suggestions["tags"] or suggestions["tags"],
-            "document_types": localized_suggestions["document_types"]
-            or suggestions["document_types"],
-            "storage_paths": localized_suggestions["storage_paths"]
-            or suggestions["storage_paths"],
-        }
+    # Hand the pooled DB connection back while the (slow) LLM query runs so it
+    # is not pinned for the call's duration; see paperless_ai.db and #12976.
+    with db_connection_released():
+        result = client.run_llm_query(prompt)
+        suggestions = parse_ai_response(result)
+        if output_language:
+            localized = client.run_llm_query(
+                build_localization_prompt(suggestions, output_language),
+            )
+            localized_suggestions = parse_ai_response(localized)
+            suggestions = {
+                **suggestions,
+                "title": localized_suggestions["title"] or suggestions["title"],
+                "tags": localized_suggestions["tags"] or suggestions["tags"],
+                "document_types": localized_suggestions["document_types"]
+                or suggestions["document_types"],
+                "storage_paths": localized_suggestions["storage_paths"]
+                or suggestions["storage_paths"],
+            }
     return suggestions