Profiles / #2
Passed Run of Oct 18, 16:02
Some tests got too few samples to explain their time.
Rerun with
pytest --flakytest-profile --flakytest-rate 1000.
Wall time
21.64 s
1 worker
Test time
17.61 s
sum of test durations
Tests
234
234 passed
Profiler
py-spy
500 Hz ·
7,300 samples · Python 3.14.8 · flakytest 2026.0b1
Peak memory
171 MB
test process
Where the time goes
Test time by category- Database6.22 s
- Libraries3.00 s
- Migrations2.74 s
- DB schema1.73 s
- Password hashing1.38 s
- Unsampled1.26 s
- Imports329 ms
- Serialization310 ms
- Templates301 ms
- App code208 ms
- pytest49 ms
- Deep copies47 ms
- Waiting19 ms
- Factories15 ms
- Test code9 ms
Session timeline
Other
1.14 s
Tests
16.34 s
Startup
212 ms
Collection
779 ms
Between tests
2.48 s
Session teardown
593 ms
Test phases
Setup 5.15 s
Call 12.34 s
Teardown 112 ms
Fix next
Ranked by the time each fix saves per run
1
Use plain static file storage in tests
Static file storage/manifest handling costs 6.0s.
High
App code
5.97 s
per run
Fix: In test settings use STORAGES["staticfiles"] = {"BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage"} so templates don't need a manifest.
Details
Where:
- apps/orgs/tests.py:30 test_signing_up_creates_an_organization · 394 ms
- apps/api/tests.py:487 upload · 304 ms
- ft/tests.py:205 test_change_password · 298 ms
- apps/mcp/tests.py:66 post · 278 ms
- ft/tests.py:161 test_signup · 175 ms
- ft/tests.py:96 test_troubleshooting · 161 ms
- apps/projects/urls.py:8 <module> · 143 ms
- apps/projects/tests.py:88 test_index_page · 136 ms
- ft/tests.py:200 test_change_password · 136 ms
- apps/orgs/views.py:32 org_shell · 104 ms
Most affected tests:
- ft/tests.py::TestAccountSettings::test_change_password
- apps/orgs/tests.py::SignupTest::test_signing_up_creates_an_organization
- apps/projects/tests.py::SeedDemoCommandTest::test_seed_demo
- ft/tests.py::TestAccountPages::test_signup
- apps/api/tests.py::TestApiIndex::test_index
- apps/projects/tests.py::ProjectPagesTest::test_dashboard_filters
- ft/tests.py::TestTrubleshootingPage::test_troubleshooting
- apps/projects/tests.py::IndexPageTest::test_index_page
2
Disable django-debug-toolbar in tests
django-debug-toolbar is installed in the test settings and costs 3.4s.
High
App code
3.42 s
per run
Fix: Only add debug_toolbar to INSTALLED_APPS and MIDDLEWARE when not testing (e.g. `if DEBUG and not TESTING:`).
Details
Where:
- apps/orgs/tests.py:30 test_signing_up_creates_an_organization · 390 ms
- ft/tests.py:205 test_change_password · 298 ms
- ft/tests.py:161 test_signup · 175 ms
- apps/projects/urls.py:8 <module> · 143 ms
- ft/tests.py:200 test_change_password · 136 ms
- apps/orgs/views.py:32 org_shell · 104 ms
- apps/api/urls.py:72 wrapped_view · 103 ms
- apps/projects/analytics.py:257 latest_profiles · 88 ms
- apps/projects/urls.py:41 can_manage_project · 75 ms
- apps/projects/urls.py:50 find_project · 73 ms
Most affected tests:
- ft/tests.py::TestAccountSettings::test_change_password
- apps/orgs/tests.py::SignupTest::test_signing_up_creates_an_organization
- apps/api/tests.py::TestApiIndex::test_index
- ft/tests.py::TestAccountPages::test_signup
- apps/projects/tests.py::ProjectPagesTest::test_dashboard_filters
- apps/projects/tests.py::SeedDemoCommandTest::test_seed_demo
- apps/api/tests.py::ProfileUploadTest::test_upload_adds_migrations_per_worker_insight
- apps/projects/tests.py::ProjectPagesTest::test_projects_page
3
Repeated queries (N+1) in the code under test
26 tests run the same query 10+ times, e.g. 180x in test_seed_demo. N+1 queries slow the tests and production alike.
High
Database
3.07 s
per run
Fix: Django: fetch related rows in one query with select_related() for foreign keys and prefetch_related() for reverse/many-to-many relations, then lock the count in with assertNumQueries (or pytest-django's django_assert_num_queries).
Details
This changes application code, so it speeds up production too; the tests stay as they are.
- 180x in test_seed_demo: SELECT "projects_test"."id", "projects_test"."name", "projects_test"."project_id", "projects_test"."slug", "projects_test"."date_last_run", "projects_test"."date_first_seen", "projects_test"."first_commit_id", "projects_test"."muted" FROM "projects_test" WHERE ("projects_test"."name" = %s AND "proj…
- 22x in test_dashboard_filters: SELECT "projects_environment"."id", "projects_environment"."project_id", "projects_environment"."name", "projects_environment"."kind", "projects_environment"."provider", "projects_environment"."details", "projects_environment"."date_first_seen", "projects_environment"."date_last_seen" FROM "project…
- 21x in test_configure_page: SELECT "projects_profile"."id", "projects_profile"."project_id", "projects_profile"."number", "projects_profile"."environment_id", "projects_profile"."session_id", "projects_profile"."run_id", "projects_profile"."commit_id", "projects_profile"."ingest_id", "projects_profile"."external_id", "project…
- 20x in test_index: SELECT "django_content_type"."model" AS "model" FROM "django_content_type" WHERE "django_content_type"."app_label" = %s
- 20x in test_daily_stats_count_a_profile_once_every_part_is_in: SELECT "projects_profilepart"."id", "projects_profilepart"."profile_id", "projects_profilepart"."index", "projects_profilepart"."count", "projects_profilepart"."checksum", "projects_profilepart"."status", "projects_profilepart"."error", "projects_profilepart"."tests_count", "projects_profilepart"."…
Most affected tests:
- apps/projects/tests.py::SeedDemoCommandTest::test_seed_demo
- apps/projects/tests.py::ProjectPagesTest::test_dashboard_filters
- apps/projects/tests.py::ProjectPagesTest::test_configure_page
- apps/api/tests.py::TestApiIndex::test_index
- apps/api/tests.py::ProfileUploadTest::test_daily_stats_count_a_profile_once_every_part_is_in
- apps/api/tests.py::IngestStartEndpointTest::test_all_test_status_types
- apps/api/tests.py::IngestStartEndpointTest::test_details_are_kept_for_failures_only
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_end_after_progress
4
Stop re-running migrations on every test run
Migrations take 2.7s per run, before the first test can start.
High
Migrations
2.46 s
per run
Fix: Run with --reuse-db (add it to addopts in pytest.ini/pyproject) so the test database survives between runs; pass --create-db when migrations change. If no test depends on data migrations, --nomigrations builds the schema straight from the models, which is faster still.
Details
CI should still build the database from scratch (no --reuse-db) so broken migrations are caught.
Where:
- apps/projects/migrations/0025_backfill_slugs_and_numbers.py:35 forwards · 2 ms
- apps/projects/migrations/0014_backfill_session_counts.py:23 backfill · 2 ms
- apps/projects/migrations/0022_backfill_organizations.py:28 forwards · 2 ms
- apps/projects/migrations/0012_backfill_session_environments.py:30 backfill · 2 ms
Most affected tests:
- apps/api/tests.py::TestApiIndex::test_index
5
Make the test database server skip durability work
Tests spend 10.7s (61%) in the database. Test databases don't need to survive a crash, so the server can skip flushing to disk.
High
Database
2.14 s
per run
Fix: For a PostgreSQL test server (Docker/CI service) start it with -c fsync=off -c synchronous_commit=off -c full_page_writes=off, and put its data directory on tmpfs; for MySQL use --innodb-flush-log-at-trx-commit=0 --skip-log-bin. Never on a server with data you need.
Details
Only affects crash safety of the throwaway test server; query behaviour is identical.
Where:
- apps/api/tests.py:76 join_workers · 132 ms
- apps/projects/profiles.py:458 write_perfs · 130 ms
- apps/projects/tests.py:953 setUp · 119 ms
- apps/projects/profiles.py:313 write_snapshots · 116 ms
- apps/projects/models.py:466 save · 105 ms
- apps/orgs/views.py:32 org_shell · 104 ms
- apps/api/urls.py:72 wrapped_view · 103 ms
- apps/projects/environments.py:63 get_or_create_environment · 100 ms
- apps/projects/models.py:230 upsert · 97 ms
- apps/api/tests.py:73 setUp · 90 ms
Most affected tests:
- apps/api/tests.py::TestApiIndex::test_index
- apps/projects/tests.py::SeedDemoCommandTest::test_seed_demo
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_start_progress_end
- apps/projects/tests.py::ProfilePagePaginationTest::test_slowest_tests_first_then_the_next_page
- apps/api/tests.py::IngestStartEndpointTest::test_results_are_counted_and_the_payload_dropped
- apps/api/tests.py::IngestStartEndpointTest::test_all_test_status_types
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_end_after_progress
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_progress_before_start
6
Use a fast password hasher in tests
1.4s (8% of test time) is spent hashing passwords. Slow hashing protects real passwords; in tests it only burns CPU.
Medium
Password hashing
1.31 s
per run
Fix: In your test settings set PASSWORD_HASHERS = ["django.contrib.auth.hashers.MD5PasswordHasher"] (currently PBKDF2PasswordHasher).
Details
Only change the hasher in test settings. Tests that assert on a specific hash format need updating.
Where:
- ft/tests.py:205 test_change_password · 298 ms
- apps/orgs/tests.py:30 test_signing_up_creates_an_organization · 197 ms
- ft/tests.py:161 test_signup · 165 ms
- ft/tests.py:230 test_projects_only_lists_your_own_even_for_superusers · 162 ms
- apps/orgs/tests.py:194 test_superusers_can_open_any_project_but_dont_list_them · 150 ms
- ft/tests.py:213 test_change_password · 142 ms
- ft/tests.py:200 test_change_password · 134 ms
- ft/tests.py:175 setUpTestData · 133 ms
Most affected tests:
- ft/tests.py::TestAccountSettings::test_change_password
- apps/orgs/tests.py::SignupTest::test_signing_up_creates_an_organization
- ft/tests.py::TestAccountPages::test_signup
- ft/tests.py::TestAccountSettings::test_projects_only_lists_your_own_even_for_superusers
- apps/orgs/tests.py::SuperuserTest::test_superusers_can_open_any_project_but_dont_list_them
7
Use TestCase instead of TransactionTestCase
900ms goes to flushing every table after tests in 11 TransactionTestCase / transaction=True / live_server tests.
Medium
DB schema
810 ms
per run
Fix: Use django.test.TestCase (or @pytest.mark.django_db without transaction=True): it wraps each test in a transaction and rolls back instead of truncating every table. Keep TransactionTestCase only for tests that need real commits (on_commit hooks can use TestCase.captureOnCommitCallbacks).
Details
Tests that rely on commit behaviour, multiple connections or a live server still need a transactional test case.
Most affected tests:
- apps/api/tests.py::IngestStartEndpointTest::test_details_are_kept_for_failures_only
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_multiple_sessions
- apps/api/tests.py::IngestStartEndpointTest::test_results_are_counted_and_the_payload_dropped
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_valid
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_end_after_progress
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_progress_before_start
- apps/api/tests.py::IngestStartEndpointTest::test_all_test_status_types
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_start_progress_end
8
Tests open new database connections over and over
Connecting to the database takes 670ms.
Medium
Database
536 ms
per run
Fix: Reuse connections: create the engine once per session (not per test) and keep the default pool (NullPool reconnects on every checkout); in Django avoid closing connections in tests (connection.close()/close_old_connections).
Details
Where:
- apps/api/tests.py:76 join_workers · 110 ms
- apps/api/tests.py:73 setUp · 46 ms
- apps/api/tasks.py:266 warm_reports · 44 ms
- apps/api/urls.py:72 wrapped_view · 41 ms
- apps/api/tests.py:928 setUp · 13 ms
- apps/api/tests.py:331 test_results_are_counted_and_the_payload_dropped · 11 ms
- apps/api/tests.py:975 setUp · 11 ms
- apps/api/tests.py:287 test_all_test_status_types · 10 ms
- apps/api/tests.py:212 test_ingest_start_progress_end · 9 ms
- apps/api/tests.py:988 test_upload_is_processed_by_the_worker · 7 ms
Most affected tests:
- apps/api/tests.py::IngestStartEndpointTest::test_all_test_status_types
- apps/api/tests.py::IngestStartEndpointTest::test_results_are_counted_and_the_payload_dropped
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_start_progress_end
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_end_after_progress
- apps/api/tests.py::IngestStartEndpointTest::test_ingest_progress_before_start
- apps/api/tests.py::IngestStartEndpointTest::test_details_are_kept_for_failures_only
- apps/api/tests.py::ProfileUploadQueueTest::test_upload_is_processed_by_the_worker
- apps/projects/tests.py::LegacyUrlTest::test_by_id
9
Create shared test data in setUpTestData instead of setUp
setUp() runs before every test and takes 556ms in total (db 542ms, library 11ms, factories 3ms) in 13 classes: SettingsTest (3 tests), ProjectsPageTest (5 tests), ProjectEditPage (6 tests), ProjectDeletePage (4 tests).
Low
Database
389 ms
per run
Fix: Move object creation that tests only read from setUp() into `@classmethod def setUpTestData(cls)`: it runs once per class and each test still sees the original rows (TestCase rolls back to a savepoint).
Details
Since Django 3.2 attributes assigned in setUpTestData are deep-copied per test, so in-memory changes don't leak between tests. Keep objects a test modifies in the database (or re-fetches) as before.
Where:
- apps/projects/tests.py:953 setUp · 124 ms
- apps/api/tests.py:73 setUp · 94 ms
- apps/projects/tests.py:100 setUp · 63 ms
- apps/projects/tests.py:142 setUp · 48 ms
- apps/projects/tests.py:268 setUp · 39 ms
- apps/orgs/tests.py:167 setUp · 32 ms
- apps/projects/tests.py:187 setUp · 24 ms
- apps/projects/tests.py:337 setUp · 23 ms
- ft/tests.py:179 setUp · 22 ms
- apps/projects/tests.py:218 setUp · 21 ms
Most affected tests:
- apps/api/tests.py::IngestStartEndpointTest::test_details_are_kept_for_failures_only
- apps/projects/tests.py::ProjectEditPage::test_project_submit
- apps/api/tests.py::IngestStartEndpointTest::test_all_test_status_types
- apps/projects/tests.py::ProjectRunsPage::test_not_logged_in
- apps/api/tests.py::ProfileUploadQueueTest::test_upload_is_processed_by_the_worker
- apps/projects/tests.py::ProjectsPageTest::test_project
- apps/projects/tests.py::ProjectsPageTest::test_no_project
- apps/projects/tests.py::ProjectPagesTest::test_dashboard_without_data_shows_setup
Tests
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Memory
The test process peaked at 197 MBSlowest fixtures
Exact setup time across the session| Fixture | Scope | Calls | Total |
|---|---|---|---|
| _django_setup_unittest | class | 49 | 3.59 s |
| django_db_setup | session | 1 | 3.58 s |
| _unittest_setUpClass_fixture_RealProfileDocumentTest | class | 1 | 230 ms |
| _unittest_setUpClass_fixture_ProjectPagesTest | class | 1 | 181 ms |
| _unittest_setUpClass_fixture_TestAccountSettings | class | 1 | 140 ms |
| _unittest_setUpClass_fixture_AnalyticsTest | class | 1 | 124 ms |
| _unittest_setUpClass_fixture_McpTest | class | 1 | 122 ms |
| _unittest_setUpClass_fixture_ProfilePagePaginationTest | class | 1 | 111 ms |
| _unittest_setUpClass_fixture_StorageTest | class | 1 | 76 ms |
| _unittest_setUpClass_fixture_MemoryTest | class | 1 | 58 ms |
| _unittest_setUpClass_fixture_FlakyReportTest | class | 1 | 48 ms |
| _unittest_setUpClass_fixture_LegacyUrlTest | class | 1 | 40 ms |
| _unittest_setUpClass_fixture_FlakyReportCacheTest | class | 1 | 32 ms |
| _unittest_setUpClass_fixture_TestProjectTestPage | class | 1 | 15 ms |
| _unittest_setUpClass_fixture_ProjectRunPage | class | 1 | 15 ms |