Add logging on deletion task start (#37498)

* Log when deletion task is started

* Log on group deletion task start

src/sentry/tasks/deletion.py

@@ -65,6 +65,14 @@ def run_deletion(deletion_id, first_pass=True):
     from sentry import deletions
     from sentry.models import ScheduledDeletion
 
+    logger.info(
+        "deletion.started",
+        extra={
+            "deletion_id": deletion_id,
+            "first_pass": first_pass,
+        },
+    )
+
     try:
         deletion = ScheduledDeletion.objects.get(id=deletion_id)
     except ScheduledDeletion.DoesNotExist:
@@ -129,6 +137,14 @@ def delete_groups(object_ids, transaction_id=None, eventstream_state=None, **kwa
     from sentry import deletions, eventstream
     from sentry.models import Group
 
+    logger.info(
+        "delete_groups.started",
+        extra={
+            "object_ids_count": len(object_ids),
+            "first_id": object_ids[0],
+        },
+    )
+
     transaction_id = transaction_id or uuid4().hex
 
     max_batch_size = 100