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3 commits

Author SHA1 Message Date
fitermay 1bc481b779 [SPARK-27070] Improve performance of DefaultPartitionCoalescer
This time tested against Scala 2.11 as well

Closes #24116 from fitermay/master.

Authored-by: fitermay <fiterman@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
2019-03-17 11:47:14 -05:00
Dongjoon Hyun 4bab69b22a Revert "[SPARK-27070] Fix performance bug in DefaultPartitionCoalescer"
This reverts commit 21db4336b0.
2019-03-15 14:56:08 -07:00
fitermay 21db4336b0 [SPARK-27070] Fix performance bug in DefaultPartitionCoalescer
When trying to coalesce a UnionRDD of two large FileScanRDDs
(each with a few million partitions) into around 8k partitions
the driver can stall for over an hour.

Profiler shows that over 90% of the time is spent in TimSort
which is invoked by `pickBin`.  This patch replaces sorting with a more
efficient `min` for the purpose of finding the least occupied
PartitionGroup

Closes #23986 from fitermay/SPARK-27070.

Authored-by: fitermay <fiterman@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
2019-03-14 20:13:18 -05:00