spark submit java.lang.NullPointerException错误

Question

I am trying to submit my spark-mongo code jar through spark on windows.I am using spark in standalone mode. I have configured spark master and two workers on same machine. I want to execute my jar with one master and two workers.I am trying to execute following command: spark-submit --master spark://localhost:7077 --deploy-mode cluster --executor-memory 5G --class spark.mongohadoop.testing3 G:\\sparkmon1.jar

I am facing following error:

Running Spark using the REST application submission protocol.
Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties
17/02/28 17:09:13 INFO RestSubmissionClient: Submitting a request to launch an application in spark://192.168.242.1:7077.
17/02/28 17:09:24 WARN RestSubmissionClient: Unable to connect to server spark://192.168.242.1:7077.
Warning: Master endpoint spark://192.168.242.1:7077 was not a REST server. Falling back to legacy submission gateway instead.
17/02/28 17:09:25 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
17/02/28 17:09:32 ERROR ClientEndpoint: Exception from cluster was: java.lang.NullPointerException
java.lang.NullPointerException
        at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
        at org.apache.hadoop.util.Shell.runCommand(Shell.java:482)
        at org.apache.hadoop.util.Shell.run(Shell.java:455)
        at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715)
        at org.apache.hadoop.fs.FileUtil.chmod(FileUtil.java:873)
        at org.apache.hadoop.fs.FileUtil.chmod(FileUtil.java:853)
        at org.apache.spark.util.Utils$.fetchFile(Utils.scala:474)
        at org.apache.spark.deploy.worker.DriverRunner.org$apache$spark$deploy$worker$DriverRunner$$downloadUserJar(DriverRunner.scala:154)
        at org.apache.spark.deploy.worker.DriverRunner$$anon$1.run(DriverRunner.scala:83

I have already set winutil path in env. why I am getting this error and what is the solution?

Answer 1

I encountered the same error on Linux but with me it was coming when the driver was getting initiated from a particular machine in my cluster, if request to launch driver was going to any other machine in cluster, ten it was working fine. So, in my cased seemed to be as an environmental issue. I then checked the code at org.apache.hadoop.util.Shell$ShellCommandExecutor class and got that it is trying to run a command but before that it tries lo run "bash" for that machine. I observed that my bash was responding slow.made some changes in bashrc and restarted my cluster. Now its working fine.