add TODO and tweak test #455

cassandra/policies.py

@@ -528,6 +528,9 @@ class ExponentialReconnectionPolicy(ReconnectionPolicy):
     a set maximum delay.
     """
 
+    # TODO: max_attempts is 64 to preserve legacy default behavior
+    # consider changing to None in major release to prevent the policy
+    # giving up forever
     def __init__(self, base_delay, max_delay, max_attempts=64):
         """
         `base_delay` and `max_delay` should be in floating point units of

tests/unit/test_policies.py

@@ -816,25 +816,30 @@ class ExponentialReconnectionPolicyTest(unittest.TestCase):
         self.assertRaises(ValueError, ExponentialReconnectionPolicy, 9000, 1)
         self.assertRaises(ValueError, ExponentialReconnectionPolicy, 1, 2,-1)
 
-    def test_schedule(self):
-        policy = ExponentialReconnectionPolicy(base_delay=2, max_delay=100, max_attempts=None)
-        i=0;
-        for delay in policy.new_schedule():
-            i += 1
-            if i > 10000:
-                break;
-        self.assertEqual(i, 10001)
+    def test_schedule_no_max(self):
+        base_delay = 2
+        max_delay = 100
+        test_iter = 10000
+        policy = ExponentialReconnectionPolicy(base_delay=base_delay, max_delay=max_delay, max_attempts=None)
+        sched_slice = list(islice(policy.new_schedule(), 0, test_iter))
+        self.assertEqual(sched_slice[0], base_delay)
+        self.assertEqual(sched_slice[-1], max_delay)
+        self.assertEqual(len(sched_slice), test_iter)
 
-        policy = ExponentialReconnectionPolicy(base_delay=2, max_delay=100, max_attempts=64)
+    def test_schedule_with_max(self):
+        base_delay = 2
+        max_delay = 100
+        max_attempts = 64
+        policy = ExponentialReconnectionPolicy(base_delay=base_delay, max_delay=max_delay, max_attempts=max_attempts)
         schedule = list(policy.new_schedule())
-        self.assertEqual(len(schedule), 64)
+        self.assertEqual(len(schedule), max_attempts)
         for i, delay in enumerate(schedule):
             if i == 0:
-                self.assertEqual(delay, 2)
+                self.assertEqual(delay, base_delay)
             elif i < 6:
                 self.assertEqual(delay, schedule[i - 1] * 2)
             else:
-                self.assertEqual(delay, 100)
+                self.assertEqual(delay, max_delay)
 
 ONE = ConsistencyLevel.ONE