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Shixiong Zhu commented on SPARK-16017: -------------------------------------- Yes. Thanks for correcting. I will submit a PR for 2.0. In the mean time, let's revert my patch for batch 1.6 as it seems too much changes for 1.6. > YarnClientSchedulerBackend now registers backends as IPs instead of Hostnames > which causes all tasks to run with RACK_LOCAL locality. > ------------------------------------------------------------------------------------------------------------------------------------- > > Key: SPARK-16017 > URL: https://issues.apache.org/jira/browse/SPARK-16017 > Project: Spark > Issue Type: Bug > Components: Spark Core > Affects Versions: 1.6.2, 2.0.0 > Reporter: Trystan Leftwich > Priority: Critical > > Since this change: > [SPARK-15395|https://issues.apache.org/jira/browse/SPARK-15395] > When registering new executor backends it registers them as IPs instead of > hostnames. This causes a flow on effect that when the Task manager is trying > to figure out what Locality tasks should run at, no tasks can be run At the > NODE_LOCAL level. > This specific call: > https://github.com/apache/spark/blob/branch-2.0/core/src/main/scala/org/apache/spark/scheduler/TaskSetManager.scala#L886 > [pendingTasksForHost|https://github.com/apache/spark/blob/branch-2.0/core/src/main/scala/org/apache/spark/scheduler/TaskSetManager.scala#L886] > are all hostnames pulled from the DFS locations while > [hasExecutorsAliveOnHost|https://github.com/apache/spark/blob/9b234b55d1b5e4a7c80e482b3e297bfb8b583a56/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala#L560], > uses > [executorsByHost|https://github.com/apache/spark/blob/branch-2.0/core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala#L98], > which are all IP's because they are populated from the RpcAddress. > As expected this causes significant performance problems, A simple count > query will take 22 seconds, But if I revert the change from > [SPARK-15395|https://issues.apache.org/jira/browse/SPARK-15395], tasks will > run with NODE_LOCAL locality and the same count will take 3 seconds. -- 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