Spark Scala Error: Exception in thread "main" java.lang.ClassNotFoundException

Question

I tried to run a spark job on a yarn cluster written in Scala, and run into this error:

[!@#$% spark-1.0.0-bin-hadoop2]$ export HADOOP_CONF_DIR="/etc/hadoop/conf"
[!@#$% spark-1.0.0-bin-hadoop2]$ ./bin/spark-submit --class "SimpleAPP" \
>     --master yarn-client \
>     test_proj/target/scala-2.10/simple-project_2.10-0.1.jar
Spark assembly has been built with Hive, including Datanucleus jars on classpath
Exception in thread "main" java.lang.ClassNotFoundException: SimpleAPP
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:270)
    at org.apache.spark.deploy.SparkSubmit$.launch(SparkSubmit.scala:289)
    at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:55)
    at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)

And this is my sbt file:

[!@#$% test_proj]$ cat simple.sbt 
name := "Simple Project"

version := "0.1"

scalaVersion := "2.10.4"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.0.0"

// We need to be able to write Avro in Parquet
// libraryDependencies += "com.twitter" % "parquet-avro" % "1.3.2"

resolvers += "Akka Repository" at "http://repo.akka.io/releases/"

this is my SimpleApp.scala program, it is the canonical one:

import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._
import org.apache.spark.SparkConf

object SimpleApp{
  def main(args: Array[String]) {
    val logFile = "/home/myname/spark-1.0.0-bin-hadoop2/README.md" // Should be some file on your system
    val conf = new SparkConf().setAppName("Simple Application")
    val sc = new SparkContext(conf)
    val logData = sc.textFile(logFile, 2).cache()
    val numAs = logData.filter(line => line.contains("a")).count()
    val numBs = logData.filter(line => line.contains("b")).count()
    println("Lines with a: %s, Lines with b: %s".format(numAs, numBs))
  }
}

sbt package is as following:

[!@#$% test_proj]$ sbt package
[info] Set current project to Simple Project (in build file:/home/myname/spark-1.0.0-bin-hadoop2/test_proj/)
[info] Compiling 1 Scala source to /home/myname/spark-1.0.0-bin-hadoop2/test_proj/target/scala-2.10/classes...
[info] Packaging /home/myname/spark-1.0.0-bin-hadoop2/test_proj/target/scala-2.10/simple-project_2.10-0.1.jar ...
[info] Done packaging.
[success] Total time: 12 s, completed Mar 3, 2015 10:57:12 PM

As suggested, I did the following:

jar tf simple-project_2.10-0.1.jar | grep .class

Something as followed shows up:

SimpleApp$$anonfun$1.class
SimpleApp$.class
SimpleApp$$anonfun$2.class
SimpleApp.class

Answer 1

Verify if the name is SimpleAPP in the jar.

Do this:

jar tf simple-project_2.10-0.1.jar | grep .class

And check if the name of the class is right.