feat: debug stuck process by sending SIGUSR1 (backport #25502) (#25527)

* fix: debug stuck process by sending SIGUSR1

It will print stack to stderr.

(cherry picked from commit 6560d45)

* fix: set sane default timeout on SMTP

(cherry picked from commit fdd74e3)

[skip ci]

---------

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/__init__.py

@@ -11,13 +11,15 @@
 Read the documentation: https://frappeframework.com/docs
 """
 import copy
+import faulthandler
 import functools
 import gc
 import importlib
 import inspect
 import json
 import os
 import re
+import signal
 import traceback
 import unicodedata
 import warnings
@@ -263,6 +265,7 @@ def init(site: str, sites_path: str = ".", new_site: bool = False, force=False)
 	if not _qb_patched.get(local.conf.db_type):
 		patch_query_execute()
 		patch_query_aggregation()
+		_register_fault_handler()
 
 	setup_module_map(include_all_apps=not (frappe.request or frappe.job or frappe.flags.in_migrate))
 
@@ -2459,6 +2462,10 @@ def wrapper(*args, **kwargs):
 	return wrapper
 
 
+def _register_fault_handler():
+	faulthandler.register(signal.SIGUSR1)
+
+
 from frappe.utils.error import log_error
 
 if _tune_gc:

frappe/email/smtp.py

@@ -2,6 +2,7 @@
 # License: MIT. See LICENSE
 
 import smtplib
+from contextlib import suppress
 
 import frappe
 from frappe import _
@@ -71,7 +72,7 @@ def session(self):
 		SMTP = smtplib.SMTP_SSL if self.use_ssl else smtplib.SMTP
 
 		try:
-			_session = SMTP(self.server, self.port)
+			_session = SMTP(self.server, self.port, timeout=2 * 60)
 			if not _session:
 				frappe.msgprint(
 					_("Could not connect to outgoing email server"), raise_exception=frappe.OutgoingEmailError
@@ -122,8 +123,9 @@ def is_session_active(self):
 				return False
 
 	def quit(self):
-		if self.is_session_active():
-			self._session.quit()
+		with suppress(TimeoutError):
+			if self.is_session_active():
+				self._session.quit()
 
 	@classmethod
 	def throw_invalid_credentials_exception(cls):