remove hierarchical code from _save_aggregate_new

Author: lobsterkatie

src/sentry/event_manager.py

@@ -1602,7 +1602,7 @@ def _save_aggregate_new(
 ) -> GroupInfo | None:
     project = event.project
 
-    primary_hashes, secondary_hashes, hashes = get_hash_values(project, job, metric_tags)
+    hashes = get_hash_values(project, job, metric_tags)[2]
 
     # Now that we've used the current and possibly secondary grouping config(s) to calculate the
     # hashes, we're free to perform a config update if needed. Future events will use the new
@@ -1615,43 +1615,11 @@ def _save_aggregate_new(
 
     group_creation_kwargs = _get_group_creation_kwargs(job)
 
-    # Because this logic is not complex enough we want to special case the situation where we
-    # migrate from a hierarchical hash to a non hierarchical hash.  The reason being that
-    # there needs to be special logic to not create orphaned hashes in migration cases
-    # but it wants a different logic to implement splitting of hierarchical hashes.
-    migrate_off_hierarchical = bool(
-        secondary_hashes
-        and secondary_hashes.hierarchical_hashes
-        and not primary_hashes.hierarchical_hashes
-    )
-
     flat_grouphashes = [
         GroupHash.objects.get_or_create(project=project, hash=hash)[0] for hash in hashes.hashes
     ]
 
-    # The root_hierarchical_hash is the least specific hash within the tree, so
-    # typically hierarchical_hashes[0], unless a hash `n` has been split in
-    # which case `root_hierarchical_hash = hierarchical_hashes[n + 1]`. Chosing
-    # this for select_for_update mostly provides sufficient synchronization
-    # when groups are created and also relieves contention by locking a more
-    # specific hash than `hierarchical_hashes[0]`.
-    existing_grouphash, root_hierarchical_hash = find_existing_grouphash_new(flat_grouphashes)
-
-    if root_hierarchical_hash is not None:
-        root_hierarchical_grouphash = GroupHash.objects.get_or_create(
-            project=project, hash=root_hierarchical_hash
-        )[0]
-
-        metadata.update(
-            hashes.group_metadata_from_hash(
-                existing_grouphash.hash
-                if existing_grouphash is not None
-                else root_hierarchical_hash
-            )
-        )
-
-    else:
-        root_hierarchical_grouphash = None
+    existing_grouphash, _ = find_existing_grouphash_new(flat_grouphashes)
 
     # In principle the group gets the same metadata as the event, so common
     # attributes can be defined in eventtypes.
@@ -1686,25 +1654,14 @@ def _save_aggregate_new(
             metric_tags["create_group_transaction.outcome"] = "no_group"
 
             all_grouphash_ids = [h.id for h in flat_grouphashes]
-            if root_hierarchical_grouphash is not None:
-                all_grouphash_ids.append(root_hierarchical_grouphash.id)
 
             all_grouphashes = list(
                 GroupHash.objects.filter(id__in=all_grouphash_ids).select_for_update()
             )
 
             flat_grouphashes = [gh for gh in all_grouphashes if gh.hash in hashes.hashes]
 
-            existing_grouphash, root_hierarchical_hash = find_existing_grouphash_new(
-                flat_grouphashes
-            )
-
-            if root_hierarchical_hash is not None:
-                root_hierarchical_grouphash = GroupHash.objects.get_or_create(
-                    project=project, hash=root_hierarchical_hash
-                )[0]
-            else:
-                root_hierarchical_grouphash = None
+            existing_grouphash, _ = find_existing_grouphash_new(flat_grouphashes)
 
             if existing_grouphash is None:
                 group = _create_group(project, event, **group_creation_kwargs)
@@ -1721,10 +1678,7 @@ def _save_aggregate_new(
                         },
                     )
 
-                if root_hierarchical_grouphash is not None:
-                    new_hashes = [root_hierarchical_grouphash]
-                else:
-                    new_hashes = list(flat_grouphashes)
+                new_hashes = list(flat_grouphashes)
 
                 GroupHash.objects.filter(id__in=[h.id for h in new_hashes]).exclude(
                     state=GroupHash.State.LOCKED_IN_MIGRATION
@@ -1773,22 +1727,7 @@ def _save_aggregate_new(
 
     is_new = False
 
-    # For the migration from hierarchical to non hierarchical we want to associate
-    # all group hashes
-    if migrate_off_hierarchical:
-        new_hashes = [h for h in flat_grouphashes if h.group_id is None]
-        if root_hierarchical_grouphash and root_hierarchical_grouphash.group_id is None:
-            new_hashes.append(root_hierarchical_grouphash)
-    elif root_hierarchical_grouphash is None:
-        # No hierarchical grouping was run, only consider flat hashes
-        new_hashes = [h for h in flat_grouphashes if h.group_id is None]
-    elif root_hierarchical_grouphash.group_id is None:
-        # The root hash is not assigned to a group.
-        # We ran multiple grouping algorithms
-        # (see secondary grouping), and the hierarchical hash is new
-        new_hashes = [root_hierarchical_grouphash]
-    else:
-        new_hashes = []
+    new_hashes = [h for h in flat_grouphashes if h.group_id is None]
 
     if new_hashes:
         # There may still be secondary hashes that we did not use to find an