Error if connections_max_idle_ms not larger than request_timeout_ms (#1688)

Author: jeffwidman

kafka/consumer/group.py

@@ -313,11 +313,15 @@ def __init__(self, *topics, **configs):
                         new_config, self.config['auto_offset_reset'])
             self.config['auto_offset_reset'] = new_config
 
+        connections_max_idle_ms = self.config['connections_max_idle_ms']
         request_timeout_ms = self.config['request_timeout_ms']
         fetch_max_wait_ms = self.config['fetch_max_wait_ms']
-        if request_timeout_ms <= fetch_max_wait_ms:
-            raise KafkaConfigurationError("Request timeout (%s) must be larger than fetch-max-wait-ms (%s)" %
-                                          (request_timeout_ms, fetch_max_wait_ms))
+        if not (fetch_max_wait_ms < request_timeout_ms < connections_max_idle_ms):
+            raise KafkaConfigurationError(
+                "connections_max_idle_ms ({}) must be larger than "
+                "request_timeout_ms ({}) which must be larger than "
+                "fetch_max_wait_ms ({})."
+                .format(connections_max_idle_ms, request_timeout_ms, fetch_max_wait_ms))
 
         metrics_tags = {'client-id': self.config['client_id']}
         metric_config = MetricConfig(samples=self.config['metrics_num_samples'],

test/test_consumer.py

@@ -15,11 +15,15 @@
 class TestKafkaConsumer:
     def test_session_timeout_larger_than_request_timeout_raises(self):
         with pytest.raises(KafkaConfigurationError):
-            KafkaConsumer(bootstrap_servers='localhost:9092', api_version=(0,9), group_id='foo', session_timeout_ms=60000, request_timeout_ms=40000)
+            KafkaConsumer(bootstrap_servers='localhost:9092', api_version=(0, 9), group_id='foo', session_timeout_ms=50000, request_timeout_ms=40000)
 
     def test_fetch_max_wait_larger_than_request_timeout_raises(self):
         with pytest.raises(KafkaConfigurationError):
-            KafkaConsumer(bootstrap_servers='localhost:9092', fetch_max_wait_ms=41000, request_timeout_ms=40000)
+            KafkaConsumer(bootstrap_servers='localhost:9092', fetch_max_wait_ms=50000, request_timeout_ms=40000)
+
+    def test_request_timeout_larger_than_connections_max_idle_ms_raises(self):
+        with pytest.raises(KafkaConfigurationError):
+            KafkaConsumer(bootstrap_servers='localhost:9092', api_version=(0, 9), request_timeout_ms=50000, connections_max_idle_ms=40000)
 
     def test_subscription_copy(self):
         consumer = KafkaConsumer('foo', api_version=(0, 10))