Add logging for service cleanup hooks in new-style BentoML services (#…

…5171)

* Add logging for new-style service shutdown hooks in app.py

Co-Authored-By: frost@bentoml.com <frost@bentoml.com>

* refactor: improve service cleanup hook logging

Co-Authored-By: frost@bentoml.com <frost@bentoml.com>

* feat: add service instance cleanup completion logging

Co-Authored-By: frost@bentoml.com <frost@bentoml.com>

* refactor: move final cleanup log after proxy closure

Co-Authored-By: frost@bentoml.com <frost@bentoml.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: frost@bentoml.com <frost@bentoml.com>

src/_bentoml_impl/server/app.py

@@ -320,16 +320,21 @@ async def destroy_instance(self, _: Starlette) -> None:
         # Call on_shutdown hook with optional ctx or context parameter
         for name, member in vars(self.service.inner).items():
             if callable(member) and getattr(member, "__bentoml_shutdown_hook__", False):
+                logger.info("Running cleanup hook: %s", name)
                 result = getattr(
                     self._service_instance, name
                 )()  # call the bound method
                 if inspect.isawaitable(result):
                     await result
+                    logger.info("Completed async cleanup hook: %s", name)
+                else:
+                    logger.info("Completed cleanup hook: %s", name)
 
         await cleanup()
         own_proxy = getattr(self._service_instance, "__self_proxy__", None)
         if isinstance(own_proxy, RemoteProxy):
             await own_proxy.close()
+        logger.info("Service instance cleanup finalized")
         self._service_instance = None
         set_current_service(None)
         await self._result_store.__aexit__(None, None, None)