Github user srowen commented on a diff in the pull request:
https://github.com/apache/spark/pull/11242#discussion_r57021251
--- Diff: core/src/main/scala/org/apache/spark/rdd/UnionRDD.scala ---
@@ -62,7 +64,23 @@ class UnionRDD[T: ClassTag](
var rdds: Seq[RDD[T]])
extends RDD[T](sc, Nil) { // Nil since we implement getDependencies
+ // Evaluate partitions in parallel. Partitions of each rdd will be
cached by the `partitions`
+ // val in `RDD`.
+ private[spark] lazy val parallelPartitionEval: Boolean = {
--- End diff --
Yeah I was referring to the side point about caching, but I likely
misunderstood. Yes getSplits is the issue. HadoopRDD has an InputFormat and it
is possible the driver calls getPartitions on it simultaneously because two
actions could be invoked in parallel. This is the basic scenario I am thinking
of though it has a bunch of variants.
---
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]
