[ https://issues.apache.org/jira/browse/SPARK-18631?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Yin Huai resolved SPARK-18631. ------------------------------ Resolution: Fixed Fix Version/s: 2.2.0 Issue resolved by pull request 16065 [https://github.com/apache/spark/pull/16065] > Avoid making data skew worse in ExchangeCoordinator > --------------------------------------------------- > > Key: SPARK-18631 > URL: https://issues.apache.org/jira/browse/SPARK-18631 > Project: Spark > Issue Type: Bug > Components: SQL > Affects Versions: 1.6.3, 2.0.2, 2.1.0 > Reporter: Mark Hamstra > Assignee: Mark Hamstra > Fix For: 2.2.0 > > > The logic to resize partitions in the ExchangeCoordinator is to not start a > new partition until the targetPostShuffleInputSize is equalled or exceeded. > This can make data skew problems worse since a number of small partitions can > first be combined as long as the combined size remains smaller than the > targetPostShuffleInputSize, and then a large, data-skewed partition can be > further combined, making it even bigger than it already was. > It's a fairly simple to change the logic to create a new partition if adding > a new piece would exceed the targetPostShuffleInputSize instead of only > creating a new partition after the targetPostShuffleInputSize has already > been exceeded. This results in a few more partitions being created by the > ExchangeCoordinator, but data skew problems are at least not made worse even > though they are not made any better. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org