Set default --max-requests for API workers to prevent unbounded RSS growth

CHANGES/7482.bugfix

@@ -0,0 +1,2 @@
+Set default ``--max-requests 10000`` and ``--max-requests-jitter 500`` for API workers
+to prevent unbounded RSS growth from glibc heap fragmentation over long-lived worker processes.

docs/admin/learn/architecture.md

@@ -23,6 +23,14 @@ Pulp's REST API is a Django application that runs standalone using the `gunicorn
     A simple way to run the REST API as a standalone service is using the provided `pulpcore-api`
     entrypoint. It is `gunicorn` based and provides many of its options.
 
+!!! note "API worker recycling"
+    By default, `pulpcore-api` enables gunicorn ``--max-requests`` and ``--max-requests-jitter`` so
+    worker processes are periodically replaced. That limits memory growth from allocator
+    fragmentation in long-lived workers. Override via gunicorn's usual mechanisms (CLI flags,
+    ``GUNICORN_CMD_ARGS``, or a config file). To **disable** recycling and keep unlimited worker
+    lifetime, pass ``--max-requests 0`` on the ``pulpcore-api`` command line (gunicorn treats
+    ``0`` as unlimited; Pulp only applies its own defaults when ``--max-requests`` was not passed
+    there). Disabling recycling is not recommended for production.
 
 The REST API should only be deployed via the `pulpcore-api` entrypoint.
 

pulpcore/app/entrypoint.py

@@ -124,6 +124,13 @@ def load_app_specific_config(self):
             PulpApiWorker.__module__ + "." + PulpApiWorker.__qualname__,
             enforced=True,
         )
+        # Gunicorn's default for max_requests is 0 (unlimited worker lifetime). Apply Pulp defaults
+        # only when the user did not pass --max-requests on the pulpcore-api CLI. An explicit
+        # --max-requests 0 means "disable recycling" and must not be replaced.
+        if self.cfg.max_requests == 0 and self.options.get("max_requests") is None:
+            self.cfg.set("max_requests", 10000)
+            if self.options.get("max_requests_jitter") is None:
+                self.cfg.set("max_requests_jitter", 500)
 
     def load(self):
         using_pulp_api_worker.set(True)