fix: reduce the number of labels added to query jobs (#1245)

* fix: reduce the number of labels added to query jobs

Fixes internal issue 386825477

* fix unit tests

Author: tswast

bigframes/core/log_adapter.py

@@ -17,7 +17,12 @@
 from typing import List
 
 _lock = threading.Lock()
-MAX_LABELS_COUNT = 64
+
+# The limit is 64 (https://cloud.google.com/bigquery/docs/labels-intro#requirements),
+# but leave a few spare for internal labels to be added.
+# See internal issue 386825477.
+MAX_LABELS_COUNT = 64 - 8
+
 _api_methods: List = []
 _excluded_methods = ["__setattr__", "__getattr__"]
 

bigframes/session/__init__.py

@@ -373,10 +373,18 @@ def close(self):
         """Delete resources that were created with this session's session_id.
         This includes BigQuery tables, remote functions and cloud functions
         serving the remote functions."""
-        self._temp_storage_manager.clean_up_tables()
-        self._remote_function_session.clean_up(
-            self.bqclient, self.cloudfunctionsclient, self.session_id
-        )
+
+        # Protect against failure when the Session is a fake for testing or
+        # failed to initialize.
+        temp_storage_manager = getattr(self, "_temp_storage_manager", None)
+        if temp_storage_manager:
+            self._temp_storage_manager.clean_up_tables()
+
+        remote_function_session = getattr(self, "_remote_function_session", None)
+        if remote_function_session:
+            self._remote_function_session.clean_up(
+                self.bqclient, self.cloudfunctionsclient, self.session_id
+            )
 
     def read_gbq(
         self,

tests/unit/core/test_log_adapter.py

@@ -16,7 +16,10 @@
 
 from bigframes.core import log_adapter
 
-MAX_LABELS_COUNT = 64
+# The limit is 64 (https://cloud.google.com/bigquery/docs/labels-intro#requirements),
+# but leave a few spare for internal labels to be added.
+# See internal issue 386825477.
+MAX_LABELS_COUNT = 56
 
 
 @pytest.fixture

tests/unit/session/test_io_bigquery.py

@@ -114,7 +114,7 @@ def test_create_job_configs_labels_length_limit_met_and_labels_is_none():
         job_configs_labels=None, api_methods=api_methods
     )
     assert labels is not None
-    assert len(labels) == 64
+    assert len(labels) == log_adapter.MAX_LABELS_COUNT
     assert "dataframe-head" in labels.values()