Track user_dir current event stream position

synapse/handlers/user_directory.py

@@ -19,6 +19,7 @@ from six import iteritems
 
 from twisted.internet import defer
 
+from prometheus_client import Gauge
 from synapse.api.constants import EventTypes, JoinRules, Membership
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage.roommember import ProfileInfo
@@ -27,6 +28,8 @@ from synapse.util.metrics import Measure
 
 logger = logging.getLogger(__name__)
 
+# Expose event stream processing position
+event_processing_position = Gauge("event_stream_processing_position", "Currently processed up to position in the event stream")
 
 class UserDirectoryHandler(object):
     """Handles querying of and keeping updated the user_directory.
@@ -163,6 +166,10 @@ class UserDirectoryHandler(object):
                 yield self._handle_deltas(deltas)
 
                 self.pos = deltas[-1]["stream_id"]
+
+                # Expose current event processing position to prometheus
+                event_processing_position.set(self.pos)
+
                 yield self.store.update_user_directory_stream_pos(self.pos)
 
     @defer.inlineCallbacks