[ https://issues.apache.org/jira/browse/SPARK-5081?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Dr. Christian Betz updated SPARK-5081: -------------------------------------- Attachment: diff.txt And diff.txt is my diff from CDH-version to pure-version. Sorry, no "this is built from git-commit-hash" line found. I'm out again, sticking to the old version! > Shuffle write increases > ----------------------- > > Key: SPARK-5081 > URL: https://issues.apache.org/jira/browse/SPARK-5081 > Project: Spark > Issue Type: Bug > Components: Shuffle > Affects Versions: 1.2.0 > Reporter: Kevin Jung > Priority: Critical > Attachments: Spark_Debug.pdf, diff.txt > > > The size of shuffle write showing in spark web UI is much different when I > execute same spark job with same input data in both spark 1.1 and spark 1.2. > At sortBy stage, the size of shuffle write is 98.1MB in spark 1.1 but 146.9MB > in spark 1.2. > I set spark.shuffle.manager option to hash because it's default value is > changed but spark 1.2 still writes shuffle output more than spark 1.1. > It can increase disk I/O overhead exponentially as the input file gets bigger > and it causes the jobs take more time to complete. > In the case of about 100GB input, for example, the size of shuffle write is > 39.7GB in spark 1.1 but 91.0GB in spark 1.2. > spark 1.1 > ||Stage Id||Description||Input||Shuffle Read||Shuffle Write|| > |9|saveAsTextFile| |1169.4KB| | > |12|combineByKey| |1265.4KB|1275.0KB| > |6|sortByKey| |1276.5KB| | > |8|mapPartitions| |91.0MB|1383.1KB| > |4|apply| |89.4MB| | > |5|sortBy|155.6MB| |98.1MB| > |3|sortBy|155.6MB| | | > |1|collect| |2.1MB| | > |2|mapValues|155.6MB| |2.2MB| > |0|first|184.4KB| | | > spark 1.2 > ||Stage Id||Description||Input||Shuffle Read||Shuffle Write|| > |12|saveAsTextFile| |1170.2KB| | > |11|combineByKey| |1264.5KB|1275.0KB| > |8|sortByKey| |1273.6KB| | > |7|mapPartitions| |134.5MB|1383.1KB| > |5|zipWithIndex| |132.5MB| | > |4|sortBy|155.6MB| |146.9MB| > |3|sortBy|155.6MB| | | > |2|collect| |2.0MB| | > |1|mapValues|155.6MB| |2.2MB| > |0|first|184.4KB| | | -- 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