Github user rxin commented on a diff in the pull request:
https://github.com/apache/spark/pull/1697#discussion_r15675968
--- Diff: core/src/main/scala/org/apache/spark/MapOutputTracker.scala ---
@@ -232,6 +232,11 @@ private[spark] class MapOutputTrackerMaster(conf:
SparkConf)
protected val mapStatuses = new TimeStampedHashMap[Int,
Array[MapStatus]]()
private val cachedSerializedStatuses = new TimeStampedHashMap[Int,
Array[Byte]]()
+ // For each shuffleId we also maintain a Map from reducerId ->
(location, size)
+ // Lazily populated whenever the statuses are requested from DAGScheduler
+ private val statusByReducer =
+ new TimeStampedHashMap[Int, HashMap[Int, Array[(BlockManagerId,
Long)]]]()
--- End diff --
should we consider sampling the map tasks to speed up the sort?
---
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 infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
