diff --git a/docker_registry/lib/index/db.py b/docker_registry/lib/index/db.py
index e9d4c68d2..9e1607364 100644
--- a/docker_registry/lib/index/db.py
+++ b/docker_registry/lib/index/db.py
@@ -113,7 +113,11 @@ def _generate_index(self, session):
         session.add(Version(id=self.version))
         for repository in self._walk_storage(store=store):
             session.add(Repository(**repository))
-        session.commit()
+        try:
+            session.commit()
+        except Exception as e:
+            logger.exception(str(e))
+            session.rollback()
 
     @retry
     def _handle_repository_created(
diff --git a/docker_registry/toolkit.py b/docker_registry/toolkit.py
index 5a35c88a7..78b36eaad 100644
--- a/docker_registry/toolkit.py
+++ b/docker_registry/toolkit.py
@@ -327,7 +327,8 @@ def wrapper(*args, **kwargs):
         try:
             result = f(*args, **kwargs)
         finally:
-            os.remove(lock_path)
+            if os.path.exists(lock_path):
+                os.remove(lock_path)
         return result
     return wrapper