perf: improve caching attachments for transactions in no-celery-mode transactions consumer (#79366)

transactions can have attachments so we need to properly handle caching
them. this should happen immediately after caching the transaction
itself in rc-processing, which is deferred (and only performed once) in
the no-celery-mode transaction consumer

src/sentry/ingest/consumer/processors.py

@@ -55,9 +55,8 @@ def trace_func(**span_kwargs):
 
 
 def process_transaction_no_celery(
-    data: MutableMapping[str, Any], project_id: int, start_time: float
+    data: MutableMapping[str, Any], project_id: int, attachments: Any, start_time: float
 ) -> None:
-
     set_current_event_project(project_id)
 
     manager = EventManager(data)
@@ -74,7 +73,8 @@ def process_transaction_no_celery(
         data = dict(data.items())
 
     with sentry_sdk.start_span(op="event_processing_store.store"):
-        event_processing_store.store(data)
+        cache_key = event_processing_store.store(data)
+    save_attachments(attachments, cache_key)
 
 
 @trace_func(name="ingest_consumer.process_event")
@@ -189,11 +189,12 @@ def process_event(
         # The no_celery_mode version of the transactions consumer skips one trip to rc-processing
         # Otherwise, we have to store the event in processing store here for the save_event task to
         # fetch later
-        if no_celery_mode and not attachments:
+        if no_celery_mode:
             cache_key = None
         else:
             with metrics.timer("ingest_consumer._store_event"):
                 cache_key = event_processing_store.store(data)
+            save_attachments(attachments, cache_key)
 
         try:
             # Records rc-processing usage broken down by
@@ -211,23 +212,12 @@ def process_event(
         except Exception:
             pass
 
-        if attachments:
-            with sentry_sdk.start_span(op="ingest_consumer.set_attachment_cache"):
-                attachment_objects = [
-                    CachedAttachment(type=attachment.pop("attachment_type"), **attachment)
-                    for attachment in attachments
-                ]
-                assert cache_key is not None
-                attachment_cache.set(
-                    cache_key, attachments=attachment_objects, timeout=CACHE_TIMEOUT
-                )
-
         if data.get("type") == "transaction":
             if no_celery_mode:
                 with sentry_sdk.start_span(op="ingest_consumer.process_transaction_no_celery"):
                     sentry_sdk.set_tag("no_celery_mode", True)
 
-                    process_transaction_no_celery(data, project_id, start_time)
+                    process_transaction_no_celery(data, project_id, attachments, start_time)
             else:
                 assert cache_key is not None
                 # No need for preprocess/process for transactions thus submit
@@ -284,6 +274,17 @@ def process_event(
         raise Retriable(exc)
 
 
+def save_attachments(attachments: Any, cache_key: str) -> None:
+    if attachments:
+        with sentry_sdk.start_span(op="ingest_consumer.set_attachment_cache"):
+            attachment_objects = [
+                CachedAttachment(type=attachment.pop("attachment_type"), **attachment)
+                for attachment in attachments
+            ]
+            assert cache_key is not None
+            attachment_cache.set(cache_key, attachments=attachment_objects, timeout=CACHE_TIMEOUT)
+
+
 @trace_func(name="ingest_consumer.process_attachment_chunk")
 @metrics.wraps("ingest_consumer.process_attachment_chunk")
 def process_attachment_chunk(message: IngestMessage) -> None: