Allow ?no_track_activity=1 to opt-out of activity tracking (#4235)

* Don't track API requests with `?no_track_activity=1` in the activity counter

allows external idle-culling scripts to avoid updating the activity counter

* Don't track kernel shutdown as kernel activity

this causes idle-kernel shutdowns to restart the idle-shutdown timer

user-requested shutdowns will still be tracked as api activity

* test ?no_track_activity=1 tracking

* Changelog for activity

jupyter_server/base/handlers.py

@@ -575,7 +575,11 @@ def content_security_policy(self):
     def update_api_activity(self):
         """Update last_activity of API requests"""
         # record activity of authenticated requests
-        if self._track_activity and getattr(self, '_user_cache', None):
+        if (
+            self._track_activity
+            and getattr(self, '_user_cache', None)
+            and self.get_argument('no_track_activity', None) is None
+        ):
             self.settings['api_last_activity'] = utcnow()
 
     def finish(self, *args, **kwargs):

jupyter_server/services/api/tests/test_api.py

@@ -1,8 +1,8 @@
 """Test the basic /api endpoints"""
 
-import requests
+from datetime import timedelta
 
-from jupyter_server._tz import isoformat
+from jupyter_server._tz import isoformat, utcnow
 from jupyter_server.utils import url_path_join
 from jupyter_server.tests.launchserver import ServerTestBase
 
@@ -30,3 +30,18 @@ def test_get_status(self):
         assert data['last_activity'].endswith('Z')
         assert data['started'].endswith('Z')
         assert data['started'] == isoformat(self.server.web_app.settings['started'])
+
+    def test_no_track_activity(self):
+        # initialize with old last api activity
+        old = utcnow() - timedelta(days=1)
+        settings = self.server.web_app.settings
+        settings['api_last_activity'] = old
+        # accessing status doesn't update activity
+        self.get('status')
+        assert settings['api_last_activity'] == old
+        # accessing with ?no_track_activity doesn't update activity
+        self.get('contents?no_track_activity=1')
+        assert settings['api_last_activity'] == old
+        # accessing without ?no_track_activity does update activity
+        self.get('contents')
+        assert settings['api_last_activity'] > old

jupyter_server/services/kernels/kernelmanager.py

@@ -296,7 +296,6 @@ def shutdown_kernel(self, kernel_id, now=False):
             kernel._activity_stream = None
         self.stop_buffering(kernel_id)
         self._kernel_connections.pop(kernel_id, None)
-        self.last_kernel_activity = utcnow()
 
         # Decrease the metric of number of kernels
         # running for the relevant kernel type by 1