From 76eb3297cd04f57cc8a647bad59994041e580414 Mon Sep 17 00:00:00 2001
From: Saqib Ansari <nextchamp.saqib@gmail.com>
Date: Fri, 10 Apr 2026 22:43:45 +0530
Subject: [PATCH] refactor: set Retry-After header directly

---
 frappe/app.py                            | 6 ------
 frappe/concurrency_limiter.py            | 4 ++--
 frappe/exceptions.py                     | 7 -------
 frappe/tests/test_concurrency_limiter.py | 6 ++----
 4 files changed, 4 insertions(+), 19 deletions(-)

diff --git a/frappe/app.py b/frappe/app.py
index d9b401cd5a..6a07c9c223 100644
--- a/frappe/app.py
+++ b/frappe/app.py
@@ -394,12 +394,6 @@ def handle_exception(e):
 	elif http_status_code == 429:
 		response = frappe.rate_limiter.respond()
 
-	elif http_status_code == 503:
-		retry_after = getattr(e, "retry_after", 10)
-		response = frappe.utils.response.report_error(503)
-		if response:
-			response.headers["Retry-After"] = str(retry_after)
-
 	else:
 		response = ErrorPage(
 			http_status_code=http_status_code, title=_("Server Error"), message=_("Uncaught Exception")
diff --git a/frappe/concurrency_limiter.py b/frappe/concurrency_limiter.py
index 04b743b5e4..0fe2e1a534 100644
--- a/frappe/concurrency_limiter.py
+++ b/frappe/concurrency_limiter.py
@@ -72,9 +72,9 @@ def concurrent_limit(limit: int | None = None, wait_timeout: int | None = None):
 			if not acquired:
 				from frappe.exceptions import ServiceUnavailableError
 
-				retry_after = max(1, int(effective_wait))
 				exc = ServiceUnavailableError(frappe._("Server is busy. Please try again in a few seconds."))
-				exc.retry_after = retry_after
+				retry_after = max(1, int(effective_wait))
+				frappe.local.response_headers.set("Retry-After", str(retry_after))
 				raise exc
 
 			try:
diff --git a/frappe/exceptions.py b/frappe/exceptions.py
index 24c8c301ab..4b73db8b9c 100644
--- a/frappe/exceptions.py
+++ b/frappe/exceptions.py
@@ -87,14 +87,7 @@ class TooManyRequestsError(Exception):
 
 
 class ServiceUnavailableError(Exception):
-	"""Raised when a concurrency limit is exceeded for an endpoint.
-
-	Set :attr:`retry_after` (seconds) before raising so that the response
-	includes a ``Retry-After`` header.
-	"""
-
 	http_status_code = 503
-	retry_after: int = 10
 
 
 class ImproperDBConfigurationError(Exception):
diff --git a/frappe/tests/test_concurrency_limiter.py b/frappe/tests/test_concurrency_limiter.py
index fe27d9c3c4..67755c2db5 100644
--- a/frappe/tests/test_concurrency_limiter.py
+++ b/frappe/tests/test_concurrency_limiter.py
@@ -91,9 +91,8 @@ class TestConcurrentLimit(IntegrationTestCase):
 			del frappe.local.request
 			frappe.cache.delete(key)
 
-	def test_service_unavailable_has_correct_http_status_and_retry_after(self):
-		"""The raised exception must carry http_status_code=503 and retry_after
-		equal to the configured wait_timeout."""
+	def test_service_unavailable_has_correct_http_status(self):
+		"""The raised exception must carry http_status_code=503."""
 		TIMEOUT = 1
 
 		@concurrent_limit(limit=1, wait_timeout=TIMEOUT)
@@ -110,7 +109,6 @@ class TestConcurrentLimit(IntegrationTestCase):
 				fn()
 			exc = ctx.exception
 			self.assertEqual(exc.http_status_code, 503)
-			self.assertEqual(exc.retry_after, TIMEOUT)
 		finally:
 			del frappe.local.request
 			frappe.cache.delete(key)