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https://issues.apache.org/jira/browse/HIVE-15313?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ferdinand Xu updated HIVE-15313:
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Assignee: liyunzhang_intel
> Add export spark.yarn.archive or spark.yarn.jars variable in Hive on Spark
> document
> -----------------------------------------------------------------------------------
>
> Key: HIVE-15313
> URL: https://issues.apache.org/jira/browse/HIVE-15313
> Project: Hive
> Issue Type: Bug
> Reporter: liyunzhang_intel
> Assignee: liyunzhang_intel
> Priority: Minor
> Attachments: performance.improvement.after.set.spark.yarn.archive.PNG
>
>
> According to
> [wiki|https://cwiki.apache.org/confluence/display/Hive/Hive+on+Spark%3A+Getting+Started],
> run queries in HOS16 and HOS20 in yarn mode.
> Following table shows the difference in query time between HOS16 and HOS20.
> ||Version||Total time||Time for Jobs||Time for preparing jobs||
> |Spark16|51|39|12|
> |Spark20|54|40|14|
> HOS20 spends more time(2 secs) on preparing jobs than HOS16. After reviewing
> the source code of spark, found that following point causes this:
> code:[Client#distribute|https://github.com/apache/spark/blob/master/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala#L546],
> In spark20, if spark cannot find spark.yarn.archive and spark.yarn.jars in
> spark configuration file, it will first copy all jars in $SPARK_HOME/jars to
> a tmp directory and upload the tmp directory to distribute cache. Comparing
> [spark16|https://github.com/apache/spark/blob/branch-1.6/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala#L1145],
>
> In spark16, it searches spark-assembly*.jar and upload it to distribute cache.
> In spark20, it spends 2 more seconds to copy all jars in $SPARK_HOME/jar to a
> tmp directory if we don't set "spark.yarn.archive" or "spark.yarn.jars".
> We can accelerate the startup of hive on spark 20 by settintg
> "spark.yarn.archive" or "spark.yarn.jars":
> set "spark.yarn.archive":
> {code}
> cd $SPARK_HOME/jars
> zip spark-archive.zip ./*.jar # this is important, enter the jars folder then
> zip
> $ hadoop fs -copyFromLocal spark-archive.zip
> $ echo "spark.yarn.archive=hdfs:///xxx:8020/spark-archive.zip" >>
> conf/spark-defaults.conf
> {code}
> set "spark.yarn.jars":
> {code}
> $ hadoop fs mkdir spark-2.0.0-bin-hadoop
> $hadoop fs -copyFromLocal $SPARK_HOME/jars/* spark-2.0.0-bin-hadoop
> $ echo "spark.yarn.jars=hdfs:///xxx:8020/spark-2.0.0-bin-hadoop/*" >>
> conf/spark-defaults.conf
> {code}
> Suggest to add this part in wiki.
> performance.improvement.after.set.spark.yarn.archive.PNG shows the detail
> performance impovement after setting spark.yarn.archive in small queries.
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