chore: Set isolation level to READ COMMITTED for testing et al. (#28628)

superset/config.py

@@ -196,6 +196,13 @@ SQLALCHEMY_DATABASE_URI = (
 # SQLALCHEMY_DATABASE_URI = 'mysql://myapp@localhost/myapp'
 # SQLALCHEMY_DATABASE_URI = 'postgresql://root:password@localhost/myapp'
 
+# The default MySQL isolation level is REPEATABLE READ whereas the default PostgreSQL
+# isolation level is READ COMMITTED. All backends should use READ COMMITTED (or similar)
+# to help ensure consistent behavior.
+SQLALCHEMY_ENGINE_OPTIONS = {
+    "isolation_level": "SERIALIZABLE",  # SQLite does not support READ COMMITTED.
+}
+
 # In order to hook up a custom password store for all SQLALCHEMY connections
 # implement a function that takes a single argument of type 'sqla.engine.url',
 # returns a password and set SQLALCHEMY_CUSTOM_PASSWORD_STORE.

tests/integration_tests/superset_test_config.py

@@ -20,6 +20,8 @@ import math
 from copy import copy
 from datetime import timedelta
 
+from sqlalchemy.engine import make_url
+
 from superset.config import *  # noqa: F403
 from superset.config import DATA_DIR
 from tests.integration_tests.superset_test_custom_template_processors import (
@@ -52,12 +54,15 @@ if "SUPERSET__SQLALCHEMY_EXAMPLES_URI" in os.environ:  # noqa: F405
 if "UPLOAD_FOLDER" in os.environ:  # noqa: F405
     UPLOAD_FOLDER = os.environ["UPLOAD_FOLDER"]  # noqa: F405
 
-if "sqlite" in SQLALCHEMY_DATABASE_URI:
+if make_url(SQLALCHEMY_DATABASE_URI).get_backend_name() == "sqlite":
     logger.warning(  # noqa: F405
         "SQLite Database support for metadata databases will be "
         "removed in a future version of Superset."
     )
 
+if make_url(SQLALCHEMY_DATABASE_URI).get_backend_name() in ("postgresql", "mysql"):
+    SQLALCHEMY_ENGINE_OPTIONS["isolation_level"] = "READ COMMITTED"  # noqa: F405
+
 # Speeding up the tests.integration_tests.
 PRESTO_POLL_INTERVAL = 0.1
 HIVE_POLL_INTERVAL = 0.1

tests/integration_tests/superset_test_config_thumbnails.py

@@ -17,6 +17,8 @@
 # type: ignore
 from copy import copy
 
+from sqlalchemy.engine import make_url
+
 from superset.config import *  # noqa: F403
 from superset.config import DATA_DIR
 
@@ -33,12 +35,15 @@ DEBUG = True
 if "SUPERSET__SQLALCHEMY_DATABASE_URI" in os.environ:  # noqa: F405
     SQLALCHEMY_DATABASE_URI = os.environ["SUPERSET__SQLALCHEMY_DATABASE_URI"]  # noqa: F405
 
-if "sqlite" in SQLALCHEMY_DATABASE_URI:
+if make_url(SQLALCHEMY_DATABASE_URI).get_backend_name() == "sqlite":
     logger.warning(  # noqa: F405
         "SQLite Database support for metadata databases will be removed \
         in a future version of Superset."
     )
 
+if make_url(SQLALCHEMY_DATABASE_URI).get_backend_name() in ("postgresql", "mysql"):
+    SQLALCHEMY_ENGINE_OPTIONS["isolation_level"] = "READ COMMITTED"  # noqa: F405
+
 SQL_SELECT_AS_CTA = True
 SQL_MAX_ROW = 666