Scala/Spark: Caused by: java.lang.ClassNotFoundException: org.apache.spark.Logging

Question

I am pretty new to scala and spark. Trying to fix my set-up of spark/scala development. I am confused by the versions and missing jars. I searched on stackoverflow, but still stuck in this issue. Maybe something missing or mis-configured.

Running commands:

me@Mycomputer:~/spark-2.1.0$ bin/spark-submit --class ETLApp /home/me/src/etl/target/scala-2.10/etl-assembly-0.1.0.jar

Output:

...
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/spark/Logging
...
Caused by: java.lang.ClassNotFoundException: org.apache.spark.Logging

build.sbt:

name := "etl"

version := "0.1.0"
scalaVersion := "2.10.5"
javacOptions ++= Seq("-source", "1.8", "-target", "1.8")
mainClass := Some("ETLApp")

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.5.2" % "provided";
libraryDependencies += "org.apache.spark" %% "spark-sql" % "1.5.2" % "provided";
libraryDependencies += "org.apache.spark" %% "spark-streaming" % "1.5.2" % "provided";
libraryDependencies += "org.apache.spark" %% "spark-streaming-kafka" % "1.5.2";
libraryDependencies += "com.datastax.spark"  %% "spark-cassandra-connector" % "1.5.0-M2";
libraryDependencies += "org.apache.curator" % "curator-recipes" % "2.6.0"
libraryDependencies += "org.apache.curator" % "curator-test" % "2.6.0"
libraryDependencies += "args4j" % "args4j" % "2.32"

java -version java version "1.8.0_101"

scala -version 2.10.5

spark version 2.1.0

Any hints welcomed. Thanks

Answer 1

in that case, your jar must bring all dependend classes along when being submitted to spark.

in maven this would be possible with the assembly plugin and the jar-with-dependencies descriptor. with sbt a quick google found this: https://github.com/sbt/sbt-assembly

Answer 2

you can change your build.sbt as follows:

name := "etl"

version := "0.1.0"

scalaVersion := "2.10.5"

scalacOptions ++= Seq("-deprecation",
  "-feature",
  "-Xfuture",
  "-encoding",
  "UTF-8",
  "-unchecked",
  "-language:postfixOps")

libraryDependencies ++= Seq(
"org.apache.spark" %% "spark-core" % "1.5.2" % Provided,
"org.apache.spark" %% "spark-sql" % "1.5.2" % Provided,
"org.apache.spark" %% "spark-streaming" % "1.5.2" %  Provided,
"org.apache.spark" %% "spark-streaming-kafka" % "1.5.2" % Provided,
"com.datastax.spark"  %% "spark-cassandra-connector" % "1.5.0-M2",
"org.apache.curator" % "curator-recipes" % "2.6.0",
"org.apache.curator" % "curator-test" % "2.6.0",
"args4j" % "args4j" % "2.32")

mainClass in assembly := Some("your.package.name.ETLApp")

assemblyJarName in assembly := s"${name.value}-${version.value}.jar"

assemblyMergeStrategy in assembly := {
  case m if m.toLowerCase.endsWith("manifest.mf") => MergeStrategy.discard
  case m if m.toLowerCase.matches("meta-inf.*\\.sf$") => MergeStrategy.discard
  case "reference.conf" => MergeStrategy.concat
  case x: String if x.contains("UnusedStubClass.class") => MergeStrategy.first
  case _ => MergeStrategy.first
}

add the sbt-assembly plugin to your plugins.sbt file under the project directory in your Project's Root directory. Running sbt assembly in the Terminal(Linux) or CMD(Windows) in the root directory of your project would download all the dependencies for you and create an U