[python] do not retry for connect exception in rest (#6942)

Author: XiaoHongbo-Hope

paimon-python/pypaimon/api/client.py

@@ -158,7 +158,7 @@ def __create_retry_strategy(max_retries: int) -> Retry:
         retry_kwargs = {
             'total': max_retries,
             'read': max_retries,
-            'connect': max_retries,
+            'connect': 0,
             'backoff_factor': 1,
             'status_forcelist': [429, 502, 503, 504],
             'raise_on_status': False,

paimon-python/pypaimon/tests/rest/test_exponential_retry_strategy.py

@@ -0,0 +1,64 @@
+"""
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+import time
+import unittest
+import requests
+from requests.exceptions import ConnectionError, ConnectTimeout, Timeout
+from urllib3.exceptions import NewConnectionError, MaxRetryError
+
+from pypaimon.api.client import ExponentialRetry
+
+
+class TestExponentialRetryStrategy(unittest.TestCase):
+
+    def setUp(self):
+        self.retry_strategy = ExponentialRetry(max_retries=5)
+
+    def test_basic_retry(self):
+        retry = ExponentialRetry._ExponentialRetry__create_retry_strategy(5)
+        
+        self.assertEqual(retry.total, 5)
+        self.assertEqual(retry.read, 5)
+        self.assertEqual(retry.connect, 0)  # Connection errors should not retry
+        
+        self.assertIn(429, retry.status_forcelist)  # Too Many Requests
+        self.assertIn(503, retry.status_forcelist)  # Service Unavailable
+        self.assertNotIn(404, retry.status_forcelist)
+
+    def test_no_retry_on_connect_error(self):
+        session = requests.Session()
+        session.mount("http://", self.retry_strategy.adapter)
+        session.mount("https://", self.retry_strategy.adapter)
+        session.timeout = (1, 1)
+
+        start_time = time.time()
+        
+        try:
+            session.get("http://192.168.255.255:9999", timeout=(1, 1))
+            self.fail("Expected ConnectionError")
+        except (ConnectionError, ConnectTimeout, Timeout, NewConnectionError, MaxRetryError):
+            elapsed = time.time() - start_time
+            self.assertLess(
+                elapsed, 5.0,
+                f"Connection error took {elapsed:.2f}s, should fail quickly without retry"
+            )
+
+
+if __name__ == '__main__':
+    unittest.main()