Add metric counter for number of persisted events

synapse/storage/events.py

@@ -27,6 +27,9 @@
 from canonicaljson import encode_canonical_json
 from collections import deque, namedtuple
 
+import synapse
+import synapse.metrics
+
 
 import logging
 import math
@@ -35,6 +38,10 @@
 logger = logging.getLogger(__name__)
 
 
+metrics = synapse.metrics.get_metrics_for(__name__)
+persist_event_counter = metrics.register_counter("persisted_events")
+
+
 def encode_json(json_object):
     if USE_FROZEN_DICTS:
         # ujson doesn't like frozen_dicts
@@ -261,6 +268,7 @@ def _persist_events(self, events_and_contexts, backfilled=False):
                         events_and_contexts=chunk,
                         backfilled=backfilled,
                     )
+                    persist_event_counter.inc_by(len(chunk))
 
     @defer.inlineCallbacks
     @log_function
@@ -278,6 +286,7 @@ def _persist_event(self, event, context, current_state=None, backfilled=False):
                         current_state=current_state,
                         backfilled=backfilled,
                     )
+                    persist_event_counter.inc()
         except _RollbackButIsFineException:
             pass