chore(alerts): Add logging behind flag for number of events in an issue (#88044)

Add logs to attempt to debug
#83685

Author: ceorourke

src/sentry/features/temporary.py

@@ -525,6 +525,8 @@ def register_temporary_features(manager: FeatureManager):
     manager.add("projects:use-eap-spans-for-metrics-explorer", ProjectFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable tagging span with whether or not we should ingest it in the EAP
     manager.add("projects:ingest-spans-in-eap", ProjectFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
+    # Enable num events in an issue debugging
+    manager.add("projects:num-events-issue-debugging", ProjectFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
 
     # Project plugin features
     manager.add("projects:plugins", ProjectPluginFeature, FeatureHandlerStrategy.INTERNAL, default=True, api_expose=True)

src/sentry/rules/processing/delayed_processing.py

@@ -529,6 +529,12 @@ def apply_delayed(project_id: int, batch_key: str | None = None, *args: Any, **k
     with metrics.timer("delayed_processing.get_condition_group_results.duration"):
         condition_group_results = get_condition_group_results(condition_groups, project)
 
+    if features.has("projects:num-events-issue-debugging", project):
+        logger.info(
+            "delayed_processing.condition_group_results",
+            extra={"project_id": project.id, "results": condition_group_results},
+        )
+
     rules_to_slow_conditions = defaultdict(list)
     for rule in alert_rules:
         rules_to_slow_conditions[rule].extend(get_slow_conditions(rule))