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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