I would like to run this code which I found in Mahout In Action:
package org.help;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.mahout.math.DenseVector;
import org.apache.mahout.math.NamedVector;
import org.apache.mahout.math.VectorWritable;
public class SeqPrep {
public static void main(String args[]) throws IOException{
List<NamedVector> apples = new ArrayList<NamedVector>();
NamedVector apple;
apple = new NamedVector(new DenseVector(new double[]{0.11, 510, 1}), "small round green apple");
apples.add(apple);
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path path = new Path("appledata/apples");
SequenceFile.Writer writer = new SequenceFile.Writer(fs, conf, path, Text.class, VectorWritable.class);
VectorWritable vec = new VectorWritable();
for(NamedVector vector : apples){
vec.set(vector);
writer.append(new Text(vector.getName()), vec);
}
writer.close();
SequenceFile.Reader reader = new SequenceFile.Reader(fs, new Path("appledata/apples"), conf);
Text key = new Text();
VectorWritable value = new VectorWritable();
while(reader.next(key, value)){
System.out.println(key.toString() + " , " + value.get().asFormatString());
}
reader.close();
}
}
I compile it with:
$ javac -classpath :/usr/local/hadoop-1.0.3/hadoop-core-1.0.3.jar:/home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT.jar:/home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-job.jar:/home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-sources.jar -d myjavac/ SeqPrep.java
I jar it:
$ jar -cvf SeqPrep.jar -C myjavac/ .
Now I'd like to run it on my local hadoop node. I've tried:
hadoop jar SeqPrep.jar org.help.SeqPrep
But I get:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/mahout/math/Vector
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
So I tried using the libjars parameter:
$ hadoop jar SeqPrep.jar org.help.SeqPrep -libjars /home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT.jar -libjars /home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-job.jar -libjars /home/hduser/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-sources.jar -libjars /home/hduser/mahout/trunk/math/target/mahout-math-0.8-SNAPSHOT.jar -libjars /home/hduser/mahout/trunk/math/target/mahout-math-0.8-SNAPSHOT-sources.jar
and got the same problem. I don't know what else to try.
My eventual goal is to be able to read a .csv file on the hadoop fs into a sparse matrix and then multiply it by a random vector.
edit: Looks like Razvan got it (note: see below for another way to do this that does not mess with your hadoop installation). For reference:
$ find /usr/local/hadoop-1.0.3/. |grep mah
/usr/local/hadoop-1.0.3/./lib/mahout-core-0.8-SNAPSHOT-tests.jar
/usr/local/hadoop-1.0.3/./lib/mahout-core-0.8-SNAPSHOT.jar
/usr/local/hadoop-1.0.3/./lib/mahout-core-0.8-SNAPSHOT-job.jar
/usr/local/hadoop-1.0.3/./lib/mahout-core-0.8-SNAPSHOT-sources.jar
/usr/local/hadoop-1.0.3/./lib/mahout-math-0.8-SNAPSHOT-sources.jar
/usr/local/hadoop-1.0.3/./lib/mahout-math-0.8-SNAPSHOT-tests.jar
/usr/local/hadoop-1.0.3/./lib/mahout-math-0.8-SNAPSHOT.jar
and then:
$hadoop jar SeqPrep.jar org.help.SeqPrep
small round green apple , small round green apple:{0:0.11,1:510.0,2:1.0}
edit: I'm trying to do this without copying the mahout jars into the hadoop lib/
$ rm /usr/local/hadoop-1.0.3/lib/mahout-*
and then of course:
hadoop jar SeqPrep.jar org.help.SeqPrep
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/mahout/math/Vector
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
Caused by: java.lang.ClassNotFoundException: org.apache.mahout.math.Vector
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
and when I try the mahout job file:
$hadoop jar ~/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-job.jar org.help.SeqPrep
Exception in thread "main" java.lang.ClassNotFoundException: org.help.SeqPrep
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
If I try to include the .jar file I made:
$ hadoop jar ~/mahout/trunk/core/target/mahout-core-0.8-SNAPSHOT-job.jar SeqPrep.jar org.help.SeqPrep
Exception in thread "main" java.lang.ClassNotFoundException: SeqPrep.jar
edit: Apparently I can only send one jar at a time to hadoop. This means I need to add the class I made into the mahout core job file:
~/mahout/trunk/core/target$ cp mahout-core-0.8-SNAPSHOT-job.jar mahout-core-0.8-SNAPSHOT-job.jar_backup
~/mahout/trunk/core/target$ cp ~/workspace/seqprep/bin/org/help/SeqPrep.class .
~/mahout/trunk/core/target$ jar uf mahout-core-0.8-SNAPSHOT-job.jar SeqPrep.class
And then:
~/mahout/trunk/core/target$ hadoop jar mahout-core-0.8-SNAPSHOT-job.jar org.help.SeqPrep
Exception in thread "main" java.lang.ClassNotFoundException: org.help.SeqPrep
edit: Ok, now I can do it without messing with my hadoop installation. I was updating the .jar wrong in that previous edit. It should be:
~/mahout/trunk/core/target$ jar uf mahout-core-0.8-SNAPSHOT-job.jar org/help/SeqPrep.class
then:
~/mahout/trunk/core/target$ hadoop jar mahout-core-0.8-SNAPSHOT-job.jar org.help.SeqPrep
small round green apple , small round green apple:{0:0.11,1:510.0,2:1.0}