Document connections_max_idle_ms

This was added in #1068 but never documented.
Fix #1497

kafka/client_async.py

@@ -79,6 +79,11 @@ class KafkaClient(object):
             the computed value. Default: 1000.
         request_timeout_ms (int): Client request timeout in milliseconds.
             Default: 30000.
+        connections_max_idle_ms: Close idle connections after the number of
+            milliseconds specified by this config. The broker closes idle
+            connections after connections.max.idle.ms, so this avoids hitting
+            unexpected socket disconnected errors on the client.
+            Default: 540000
         retry_backoff_ms (int): Milliseconds to backoff when retrying on
             errors. Default: 100.
         max_in_flight_requests_per_connection (int): Requests are pipelined

kafka/consumer/group.py

@@ -212,6 +212,11 @@ class KafkaConsumer(six.Iterator):
         api_version_auto_timeout_ms (int): number of milliseconds to throw a
             timeout exception from the constructor when checking the broker
             api version. Only applies if api_version set to 'auto'
+        connections_max_idle_ms: Close idle connections after the number of
+            milliseconds specified by this config. The broker closes idle
+            connections after connections.max.idle.ms, so this avoids hitting
+            unexpected socket disconnected errors on the client.
+            Default: 540000
         metric_reporters (list): A list of classes to use as metrics reporters.
             Implementing the AbstractMetricsReporter interface allows plugging
             in classes that will be notified of new metric creation. Default: []

kafka/producer/kafka.py

@@ -171,6 +171,11 @@ class KafkaProducer(object):
             will block up to max_block_ms, raising an exception on timeout.
             In the current implementation, this setting is an approximation.
             Default: 33554432 (32MB)
+        connections_max_idle_ms: Close idle connections after the number of
+            milliseconds specified by this config. The broker closes idle
+            connections after connections.max.idle.ms, so this avoids hitting
+            unexpected socket disconnected errors on the client.
+            Default: 540000
         max_block_ms (int): Number of milliseconds to block during
             :meth:`~kafka.KafkaProducer.send` and
             :meth:`~kafka.KafkaProducer.partitions_for`. These methods can be