From da8801f1504855f4f8838807c31a22d9c29b1e57 Mon Sep 17 00:00:00 2001
From: Prajna1999 <gituprajna20@gmail.com>
Date: Tue, 7 Apr 2026 12:12:37 +0530
Subject: [PATCH 1/3] fix: conditional connection pool sizes for staging and
 development

---
 backend/app/core/db.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/backend/app/core/db.py b/backend/app/core/db.py
index 510e9da74..3f4a2aa5b 100644
--- a/backend/app/core/db.py
+++ b/backend/app/core/db.py
@@ -11,9 +11,16 @@ def get_engine():
 
     # Configure connection pool settings
     # For testing, we need more connections since tests run in parallel
-    pool_size = 20 if settings.ENVIRONMENT == "development" else 5
-    max_overflow = 30 if settings.ENVIRONMENT == "development" else 10
-
+    pool_size = 5
+    max_overflow = 10
+
+    if settings.ENVIRONMENT == "development":
+        pool_size = 20
+        max_overflow = 30
+    elif settings.ENVIRONMENT == "staging":
+        pool_size = 12
+        # test it out
+        max_overflow = 0
     return create_engine(
         str(settings.SQLALCHEMY_DATABASE_URI),
         pool_size=pool_size,

From 646aa949f383e511d5488451a2652fdaf335fb5c Mon Sep 17 00:00:00 2001
From: Prajna1999 <gituprajna20@gmail.com>
Date: Tue, 7 Apr 2026 12:14:11 +0530
Subject: [PATCH 2/3] bump pool size to 16 for redundancy

---
 backend/app/core/db.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/backend/app/core/db.py b/backend/app/core/db.py
index 3f4a2aa5b..91b0966ac 100644
--- a/backend/app/core/db.py
+++ b/backend/app/core/db.py
@@ -18,7 +18,7 @@ def get_engine():
         pool_size = 20
         max_overflow = 30
     elif settings.ENVIRONMENT == "staging":
-        pool_size = 12
+        pool_size = 16
         # test it out
         max_overflow = 0
     return create_engine(

From 9d826471715bc18abe9af28f2d3b4017c24f20fe Mon Sep 17 00:00:00 2001
From: Prajna1999 <gituprajna20@gmail.com>
Date: Thu, 9 Apr 2026 08:43:06 +0530
Subject: [PATCH 3/3] fix: logger to track checked out db connections

---
 backend/app/celery/celery_app.py | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/backend/app/celery/celery_app.py b/backend/app/celery/celery_app.py
index 45364a72f..975948600 100644
--- a/backend/app/celery/celery_app.py
+++ b/backend/app/celery/celery_app.py
@@ -1,7 +1,7 @@
 import logging
 
 from celery import Celery
-from celery.signals import worker_process_init
+from celery.signals import task_prerun, worker_process_init
 from kombu import Exchange, Queue
 
 from app.core.config import settings
@@ -9,6 +9,24 @@
 logger = logging.getLogger(__name__)
 
 
+@task_prerun.connect
+def log_pool_status(task: "celery.Task", **_: object) -> None:  # type: ignore[name-defined]
+    """Log DB connection pool state before each task to detect connection leaks.
+
+    If checked_out equals pool size right when a task starts, connections
+    are being held across tasks (likely across LLM API calls) and leaking.
+    """
+    from app.core.db import engine
+    from sqlalchemy.pool import QueuePool
+
+    pool = engine.pool
+    if isinstance(pool, QueuePool):
+        logger.info(
+            f"[pool] task={task.name} checked_out={pool.checkedout()} "
+            f"size={pool.size()} overflow={pool.overflow()}"
+        )
+
+
 @worker_process_init.connect
 def warm_llm_modules(**_) -> None:
     """Import LLM service modules in each worker process right after fork.