Github user tdas commented on a diff in the pull request:
https://github.com/apache/spark/pull/15387#discussion_r82370539
--- Diff:
external/kafka-0-10/src/main/scala/org/apache/spark/streaming/kafka010/DirectKafkaInputDStream.scala
---
@@ -223,7 +223,7 @@ private[spark] class DirectKafkaInputDStream[K, V](
override def start(): Unit = {
val c = consumer
- c.poll(0)
+ assert(c.poll(0).isEmpty, "Driver shouldn't consume messages; pause if
you poll during setup")
--- End diff --
Is this poll(0) guaranteed to not return any record if the previous poll(0)
is paused immediately? Is there a race condition possible where the first
poll(0) (inside consumer strategy) manages to actually fetch records internally
before it is paused, which is then returned by this poll(0) (inside DStream)?
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
