Running spark scala example fails

Question

I'm new to both Spark and Scala. I've created an IntelliJ Scala project with SBT and added a few lines to build.sbt.

name := "test-one"  version := "1.0"  scalaVersion := "2.11.2"  libraryDependencies += "org.apache.spark" % "spark-core_2.10" % "1.1.0" 

My version of Scala is 2.10.4 but this problem also occurs with 2.11.2

Exception in thread "main" java.lang.NoClassDefFoundError: scala/collection/GenTraversableOnce$class     at akka.util.Collections$EmptyImmutableSeq$.<init>(Collections.scala:15)     at akka.util.Collections$EmptyImmutableSeq$.<clinit>(Collections.scala)     at akka.japi.Util$.immutableSeq(JavaAPI.scala:209)     at akka.actor.ActorSystem$Settings.<init>(ActorSystem.scala:150)     at akka.actor.ActorSystemImpl.<init>(ActorSystem.scala:470)     at akka.actor.ActorSystem$.apply(ActorSystem.scala:111)     at akka.actor.ActorSystem$.apply(ActorSystem.scala:104)     at org.apache.spark.util.AkkaUtils$.org$apache$spark$util$AkkaUtils$$doCreateActorSystem(AkkaUtils.scala:121)     at org.apache.spark.util.AkkaUtils$$anonfun$1.apply(AkkaUtils.scala:54)     at org.apache.spark.util.AkkaUtils$$anonfun$1.apply(AkkaUtils.scala:53)     at org.apache.spark.util.Utils$$anonfun$startServiceOnPort$1.apply$mcVI$sp(Utils.scala:1446)     at scala.collection.immutable.Range.foreach$mVc$sp(Range.scala:160)     at org.apache.spark.util.Utils$.startServiceOnPort(Utils.scala:1442)     at org.apache.spark.util.AkkaUtils$.createActorSystem(AkkaUtils.scala:56)     at org.apache.spark.SparkEnv$.create(SparkEnv.scala:153)     at org.apache.spark.SparkContext.<init>(SparkContext.scala:203)     at TweeProcessor$.main(TweeProcessor.scala:10)     at TweeProcessor.main(TweeProcessor.scala)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)     at java.lang.reflect.Method.invoke(Method.java:606)     at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134) Caused by: java.lang.ClassNotFoundException: scala.collection.GenTraversableOnce$class     at java.net.URLClassLoader$1.run(URLClassLoader.java:366)     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)     at java.security.AccessController.doPrivileged(Native Method)     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)     ... 23 more 

Tried looking up online, most answers point to a mismatch between API versions and Scala version, but none are specific to Spark.

Answer 1

spark-core_2.10 is built for use with 2.10.x versions of scala. You should use

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.1.0" 

which will select the correct _2.10 or _2.11 version for your scala version.

Also make sure you're compiling against the same versions of scala and spark as the ones on the cluster where you're running this.

Answer 2

Downgrade the scala version to 2.10.4

name := "test-one"  version := "1.0"  //scalaVersion := "2.11.2" scalaVersion := "2.10.4"  libraryDependencies += "org.apache.spark" % "spark-core_2.10" % "1.1.0"