1 files changed, 20 insertions, 1 deletions
diff --git a/synapse/storage/controllers/persist_events.py b/synapse/storage/controllers/persist_events.py
index f34c067515..bb14729a9d 100644
--- a/synapse/storage/controllers/persist_events.py
+++ b/synapse/storage/controllers/persist_events.py
@@ -46,7 +46,14 @@ from synapse.api.constants import EventTypes, Membership
 from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
-from synapse.logging.tracing import Link, get_active_span, start_active_span, trace
+from synapse.logging.tracing import (
+    Link,
+    SynapseTags,
+    get_active_span,
+    set_attribute,
+    start_active_span,
+    trace,
+)
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage.controllers.state import StateStorageController
 from synapse.storage.databases import Databases
@@ -383,9 +390,21 @@ class EventsPersistenceStorageController:
             PartialStateConflictError: if attempting to persist a partial state event in
                 a room that has been un-partial stated.
         """
+        event_ids: List[str] = []
         partitioned: Dict[str, List[Tuple[EventBase, EventContext]]] = {}
         for event, ctx in events_and_contexts:
             partitioned.setdefault(event.room_id, []).append((event, ctx))
+            event_ids.append(event.event_id)
+
+        set_attribute(
+            SynapseTags.FUNC_ARG_PREFIX + "event_ids",
+            str(event_ids),
+        )
+        set_attribute(
+            SynapseTags.FUNC_ARG_PREFIX + "event_ids.length",
+            str(len(event_ids)),
+        )
+        set_attribute(SynapseTags.FUNC_ARG_PREFIX + "backfilled", str(backfilled))
 
         async def enqueue(
             item: Tuple[str, List[Tuple[EventBase, EventContext]]]