问题
I want to run a spark streaming application on a yarn cluster on a remote server. The default java version is 1.7 but i want to use 1.8 for my application which is also there in the server but is not the default. Is there a way to specify through spark-submit the location of java 1.8 so that i do not get major.minor error ?
回答1:
JAVA_HOME was not enough in our case, the driver was running in java 8, but I discovered later that Spark workers in YARN were launched using java 7 (hadoop nodes have both java version installed).
I had to add spark.executorEnv.JAVA_HOME=/usr/java/<version available in workers> in spark-defaults.conf. Note that you can provide it in command line with --conf.
See http://spark.apache.org/docs/latest/configuration.html#runtime-environment
回答2:
Although you can force the Driver code to run on a particular Java version (export JAVA_HOME=/path/to/jre/ && spark-submit ...
), the workers will execute the code with the default Java version from the yarn user's PATH from the worker machine.
What you can do is set each Spark instance to use a particular JAVA_HOME by editing the spark-env.sh files (documentation).
回答3:
Add JAVA_HOME that you want in spark-env.sh (sudo find -name spark-env.sh ...ej. : /etc/spark2/conf.cloudera.spark2_on_yarn/spark-env.sh)
回答4:
If you want to set java environment for spark on yarn, you can set it before spark-submit
--conf spark.yarn.appMasterEnv.JAVA_HOME=/usr/java/jdk1.8.0_121 \
回答5:
The Java version would need to be set for both the Spark App Master and the Spark Executors which will be launched on YARN. Thus the spark-submit command must include two JAVA_HOME settings: spark.executorEnv.JAVA_HOME and spark.yarn.appMasterEnv.JAVA_HOME
spark-submit --class com.example.DataFrameExample --conf "spark.executorEnv.JAVA_HOME=/jdk/jdk1.8.0_162" --conf "spark.yarn.appMasterEnv.JAVA_HOME=/jdk/jdk1.8.0_162" --master yarn --deploy-mode client /spark/programs/DataFrameExample/target/scala-2.12/dfexample_2.12-1.0.jar
来源：https://stackoverflow.com/questions/36863599/how-to-specify-which-java-version-to-use-in-spark-submit-command