NoClassDefFoundError when running mahout spark-itemsimilarity

Question

I am new to mahout and want to run the command "mahout spark-itemsimilarity" according to this page intro-coocurrence-spark. However I get the following error, I googled a lot but still get nothing related to this?

./bin/mahout spark-itemsimilarity
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/spark/SparkConf
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: org.apache.spark.SparkConf
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 7 more

I am using Ubuntu and set up JAVA_HOME, MAHOUT_HOME, SPARK_HOME. what else I should do?

forgot to mention the versions I used, mahout 0.12.2, Hadoop 2.7.3 — bojan
This looks like a Spark setup problem because one of the first things Spark looks for is SparkConf. Are you able to run any of the Spark demo apps or the Spark Scala shell? — pferrel
spark version is 2.1.0. I haven't run any spark demo yet, I will do it. I saw some spark jar files included in the mahout folder, does that still need spark anymore? — bojan

BJ_ BJ_ · Accepted Answer · 2017-05-14T17:39:33

I also got this error after running the command "mahout spark-itemsimilarity".

I managed to get rid of this error by reverting to spark-1.6.3-bin-hadoop2.4 in the directory to which SPARK_HOME points.

The idea to try this approach came as a result of reading 'Building From Source' section of README.md in a Mahout's directory, which I didn't read before because I use pre-built Mahout binaries.

NoClassDefFoundError when running mahout spark-itemsimilarity

1 Answers