[jira] [Created] (HIVE-15313) Add export spark.yarn.archive or spark.yarn.jars variable in Hive on Spark document

["liyunzhang_intel (JIRA)" <ji...@apache.org>]

liyunzhang_intel created HIVE-15313:
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             Summary: 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
            Priority: Minor


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 will find 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.

We can accelerate the startup of hive on spark 20 by settintg "spark.yarn.archive" or "spark.yarn.jars":
set "spark.yarn.archive":
{code}
 zip spark-archive.zip $SPARK_HOME/jars/*
$ 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.







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