From e1a2b370d8b53ec120f621452219779ce710411e Mon Sep 17 00:00:00 2001
From: "sentry[bot]" <39604003+sentry[bot]@users.noreply.github.com>
Date: Fri, 19 Jun 2026 19:18:11 +0000
Subject: [PATCH] perf(worker): Optimize N+1 queries in ProcessFlakesTask

---
 .../test_analytics/ta_process_flakes.py       | 60 +++++++++++++++----
 1 file changed, 50 insertions(+), 10 deletions(-)

diff --git a/apps/worker/services/test_analytics/ta_process_flakes.py b/apps/worker/services/test_analytics/ta_process_flakes.py
index 61cf26df09..7bc846de65 100644
--- a/apps/worker/services/test_analytics/ta_process_flakes.py
+++ b/apps/worker/services/test_analytics/ta_process_flakes.py
@@ -42,7 +42,27 @@ def get_testruns(upload: ReportSession) -> QuerySet[Testrun]:
     ).order_by("timestamp")
 
 
-def handle_pass(curr_flakes: dict[bytes, Flake], test_id: bytes):
+def get_testruns_for_uploads(
+    uploads: list[ReportSession],
+) -> dict[int, list[Testrun]]:
+    """Fetch all testruns for a list of uploads in a single query, grouped by upload_id."""
+    upload_ids = [upload.id for upload in uploads]
+    testruns = Testrun.objects.filter(
+        Q(timestamp__gte=timezone.now() - timedelta(days=1))
+        & Q(upload_id__in=upload_ids)
+    ).order_by("timestamp")
+
+    grouped: dict[int, list[Testrun]] = {upload_id: [] for upload_id in upload_ids}
+    for testrun in testruns:
+        grouped[testrun.upload_id].append(testrun)
+    return grouped
+
+
+def handle_pass(
+    curr_flakes: dict[bytes, Flake],
+    test_id: bytes,
+    expired_flakes: list[Flake],
+):
     # possible that we expire it and stop caring about it
     if test_id not in curr_flakes:
         return
@@ -51,7 +71,7 @@ def handle_pass(curr_flakes: dict[bytes, Flake], test_id: bytes):
     curr_flakes[test_id].count += 1
     if curr_flakes[test_id].recent_passes_count == 30:
         curr_flakes[test_id].end_date = timezone.now()
-        curr_flakes[test_id].save()
+        expired_flakes.append(curr_flakes[test_id])
         del curr_flakes[test_id]
 
 
@@ -81,10 +101,12 @@ def handle_failure(
 
 @sentry_sdk.trace
 def process_single_upload(
-    upload: ReportSession, curr_flakes: dict[bytes, Flake], repo_id: int
-):
-    testruns = get_testruns(upload)
-
+    upload: ReportSession,
+    testruns: list[Testrun],
+    curr_flakes: dict[bytes, Flake],
+    repo_id: int,
+    expired_flakes: list[Flake],
+) -> list[Testrun]:
     for testrun in testruns:
         test_id = bytes(testrun.test_id)
         match testrun.outcome:
@@ -92,13 +114,13 @@ def process_single_upload(
                 if test_id not in curr_flakes:
                     continue
 
-                handle_pass(curr_flakes, test_id)
+                handle_pass(curr_flakes, test_id, expired_flakes)
             case "failure" | "flaky_fail" | "error":
                 handle_failure(curr_flakes, test_id, testrun, repo_id)
             case _:
                 continue
 
-    Testrun.objects.bulk_update(testruns, ["outcome"])
+    return testruns
 
 
 @sentry_sdk.trace
@@ -106,7 +128,7 @@ def process_flakes_for_commit(repo_id: int, commit_id: str):
     log.info(
         "process_flakes_for_commit: starting processing",
     )
-    uploads = get_relevant_uploads(repo_id, commit_id)
+    uploads = list(get_relevant_uploads(repo_id, commit_id))
 
     log.info(
         "process_flakes_for_commit: fetched uploads",
@@ -120,8 +142,18 @@ def process_flakes_for_commit(repo_id: int, commit_id: str):
         extra={"flakes": [flake.test_id.hex() for flake in curr_flakes.values()]},
     )
 
+    # Fetch all testruns for all uploads in a single query
+    testruns_by_upload = get_testruns_for_uploads(uploads)
+
+    all_modified_testruns: list[Testrun] = []
+    expired_flakes: list[Flake] = []
+
     for upload in uploads:
-        process_single_upload(upload, curr_flakes, repo_id)
+        testruns = testruns_by_upload.get(upload.id, [])
+        modified = process_single_upload(
+            upload, testruns, curr_flakes, repo_id, expired_flakes
+        )
+        all_modified_testruns.extend(modified)
         log.info(
             "process_flakes_for_commit: processed upload",
             extra={"upload": upload.id},
@@ -132,6 +164,14 @@ def process_flakes_for_commit(repo_id: int, commit_id: str):
         extra={"flakes": [flake.test_id.hex() for flake in curr_flakes.values()]},
     )
 
+    # Single bulk_update for all modified testruns across all uploads
+    if all_modified_testruns:
+        Testrun.objects.bulk_update(all_modified_testruns, ["outcome"])
+
+    # Batch-update expired flakes instead of individual .save() calls
+    if expired_flakes:
+        Flake.objects.bulk_update(expired_flakes, ["end_date", "count", "recent_passes_count"])
+
     Flake.objects.bulk_create(
         curr_flakes.values(),
         update_conflicts=True,