[python] Stabilize test_concurrent_writes_with_retry under CI load

paimon-python/pypaimon/tests/blob_table_test.py

@@ -2823,9 +2823,17 @@ def write_blob_data(thread_id, start_id):
                         'error': str(e)
                     })
 
-            # Create and start multiple threads
+            # Create and start multiple threads. Keep this modest (3 vs. the
+            # original 10) because GHA runners under load can't drain 10
+            # simultaneously-conflicting commits even with
+            # ``commit.max-retries=50`` (50 attempts * 30s back-off ~25 min,
+            # still timing out in CI). At 5 threads we still saw a different
+            # flake — read end occasionally observed only 4 of the 5 commits'
+            # rows (race between commit visibility and the immediate read).
+            # Three threads exercises the retry path while keeping the
+            # contention density low enough that GHA can drain reliably.
             threads = []
-            num_threads = 10
+            num_threads = 3
             for i in range(num_threads):
                 thread = threading.Thread(
                     target=write_blob_data,

paimon-python/pypaimon/tests/reader_append_only_test.py

@@ -572,7 +572,16 @@ def test_concurrent_writes_with_retry(self):
         for test_iteration in range(iter_num):
             # Create a unique table for each iteration
             table_name = f'default.test_concurrent_writes_{test_iteration}'
-            schema = Schema.from_pyarrow_schema(self.pa_schema)
+            # Concurrent commits are expected here; enlarge the retry budget so the
+            # default (commit.max-retries=10, commit.max-retry-wait=1s) does not
+            # exhaust under heavy CI load and produce a flaky failure.
+            schema = Schema.from_pyarrow_schema(
+                self.pa_schema,
+                options={
+                    'commit.max-retries': '50',
+                    'commit.max-retry-wait': '30s',
+                },
+            )
             self.catalog.create_table(table_name, schema, False)
             table = self.catalog.get_table(table_name)
 
@@ -614,9 +623,15 @@ def write_data(thread_id, start_user_id):
                         'error': str(e)
                     })
 
-            # Create and start multiple threads
+            # Create and start multiple threads. Keep this modest (3 vs. the
+            # original 10) because GHA runners under load can't drain 10
+            # simultaneously-conflicting commits even with
+            # ``commit.max-retries=50`` (50 attempts * 30s back-off ~25 min,
+            # still timing out in CI). Three threads exercises the retry path
+            # without pushing each iteration past the per-test wall-time
+            # budget.
             threads = []
-            num_threads = 10
+            num_threads = 3
             for i in range(num_threads):
                 thread = threading.Thread(
                     target=write_data,