Add more metrics to push rule evaluation

synapse/push/bulk_push_rule_evaluator.py

@@ -20,6 +20,8 @@ from twisted.internet import defer
 from .push_rule_evaluator import PushRuleEvaluatorForEvent
 
 from synapse.api.constants import EventTypes, Membership
+from synapse.metrics import get_metrics_for
+from synapse.util.caches import metrics as cache_metrics
 from synapse.util.caches.descriptors import cached
 from synapse.util.async import Linearizer
 
@@ -31,6 +33,23 @@ logger = logging.getLogger(__name__)
 
 rules_by_room = {}
 
+push_metrics = get_metrics_for(__name__)
+
+push_rules_invalidation_counter = push_metrics.register_counter(
+    "push_rules_invalidation_counter"
+)
+push_rules_state_size_counter = push_metrics.register_counter(
+    "push_rules_state_size_counter"
+)
+
+# Measures whether we use the fast path of using state deltas, or if we have to
+# recalculate from scratch
+push_rules_delta_state_cache_metric = cache_metrics.register_cache(
+    "cache",
+    size_callback=lambda: 0,  # Meaningless size, as this isn't a cache that stores values
+    cache_name="push_rules_delta_state_cache_metric",
+)
+
 
 class BulkPushRuleEvaluator(object):
     """Calculates the outcome of push rules for an event for all users in the
@@ -41,6 +60,12 @@ class BulkPushRuleEvaluator(object):
         self.hs = hs
         self.store = hs.get_datastore()
 
+        self.room_push_rule_cache_metrics = cache_metrics.register_cache(
+            "cache",
+            size_callback=lambda: 0,  # There's not good value for this
+            cache_name="room_push_rule_cache",
+        )
+
     @defer.inlineCallbacks
     def _get_rules_for_event(self, event, context):
         """This gets the rules for all users in the room at the time of the event,
@@ -78,7 +103,10 @@ class BulkPushRuleEvaluator(object):
         # It's important that RulesForRoom gets added to self._get_rules_for_room.cache
         # before any lookup methods get called on it as otherwise there may be
         # a race if invalidate_all gets called (which assumes its in the cache)
-        return RulesForRoom(self.hs, room_id, self._get_rules_for_room.cache)
+        return RulesForRoom(
+            self.hs, room_id, self._get_rules_for_room.cache,
+            self.room_push_rule_cache_metrics,
+        )
 
     @defer.inlineCallbacks
     def action_for_event_by_user(self, event, context):
@@ -161,17 +189,19 @@ class RulesForRoom(object):
     the entire cache for the room.
     """
 
-    def __init__(self, hs, room_id, rules_for_room_cache):
+    def __init__(self, hs, room_id, rules_for_room_cache, room_push_rule_cache_metrics):
         """
         Args:
             hs (HomeServer)
             room_id (str)
             rules_for_room_cache(Cache): The cache object that caches these
                 RoomsForUser objects.
+            room_push_rule_cache_metrics (CacheMetric)
         """
         self.room_id = room_id
         self.is_mine_id = hs.is_mine_id
         self.store = hs.get_datastore()
+        self.room_push_rule_cache_metrics = room_push_rule_cache_metrics
 
         self.linearizer = Linearizer(name="rules_for_room")
 
@@ -215,13 +245,17 @@ class RulesForRoom(object):
 
         if state_group and self.state_group == state_group:
             logger.debug("Using cached rules for %r", self.room_id)
+            self.room_push_rule_cache_metrics.inc_hits()
             defer.returnValue(self.rules_by_user)
 
         with (yield self.linearizer.queue(())):
             if state_group and self.state_group == state_group:
                 logger.debug("Using cached rules for %r", self.room_id)
+                self.room_push_rule_cache_metrics.inc_hits()
                 defer.returnValue(self.rules_by_user)
 
+            self.room_push_rule_cache_metrics.inc_misses()
+
             ret_rules_by_user = {}
             missing_member_event_ids = {}
             if state_group and self.state_group == context.prev_group:
@@ -229,8 +263,13 @@ class RulesForRoom(object):
                 # results.
                 ret_rules_by_user = self.rules_by_user
                 current_state_ids = context.delta_ids
+
+                push_rules_delta_state_cache_metric.inc_hits()
             else:
                 current_state_ids = context.current_state_ids
+                push_rules_delta_state_cache_metric.inc_misses()
+
+            push_rules_state_size_counter.inc_by(len(current_state_ids))
 
             logger.debug(
                 "Looking for member changes in %r %r", state_group, current_state_ids
@@ -375,6 +414,7 @@ class RulesForRoom(object):
         self.state_group = object()
         self.member_map = {}
         self.rules_by_user = {}
+        push_rules_invalidation_counter.inc()
 
     def update_cache(self, sequence, members, rules_by_user, state_group):
         if sequence == self.sequence: