1 files changed, 25 insertions, 8 deletions
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index cf82a2336e..7a3c16a8aa 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -52,6 +52,11 @@ bump_active_time_counter = metrics.register_counter("bump_active_time")
 
 get_updates_counter = metrics.register_counter("get_updates", labels=["type"])
 
+notify_reason_counter = metrics.register_counter("notify_reason", labels=["reason"])
+state_transition_counter = metrics.register_counter(
+    "state_transition", labels=["from", "to"]
+)
+
 
 # If a user was last active in the last LAST_ACTIVE_GRANULARITY, consider them
 # "currently_active"
@@ -646,6 +651,13 @@ class PresenceHandler(object):
                 )
                 continue
 
+            if get_domain_from_id(user_id) != origin:
+                logger.info(
+                    "Got presence update from %r with bad 'user_id': %r",
+                    origin, user_id,
+                )
+                continue
+
             presence_state = push.get("presence", None)
             if not presence_state:
                 logger.info(
@@ -939,27 +951,32 @@ class PresenceHandler(object):
 def should_notify(old_state, new_state):
     """Decides if a presence state change should be sent to interested parties.
     """
+    if old_state == new_state:
+        return False
+
     if old_state.status_msg != new_state.status_msg:
+        notify_reason_counter.inc("status_msg_change")
         return True
 
-    if old_state.state == PresenceState.ONLINE:
-        if new_state.state != PresenceState.ONLINE:
-            # Always notify for online -> anything
-            return True
+    if old_state.state != new_state.state:
+        notify_reason_counter.inc("state_change")
+        state_transition_counter.inc(old_state.state, new_state.state)
+        return True
 
+    if old_state.state == PresenceState.ONLINE:
         if new_state.currently_active != old_state.currently_active:
+            notify_reason_counter.inc("current_active_change")
             return True
 
         if new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY:
             # Only notify about last active bumps if we're not currently acive
-            if not (old_state.currently_active and new_state.currently_active):
+            if not new_state.currently_active:
+                notify_reason_counter.inc("last_active_change_online")
                 return True
 
     elif new_state.last_active_ts - old_state.last_active_ts > LAST_ACTIVE_GRANULARITY:
         # Always notify for a transition where last active gets bumped.
-        return True
-
-    if old_state.state != new_state.state:
+        notify_reason_counter.inc("last_active_change_not_online")
         return True
 
     return False