Hi,
I am new to mahout, and am working my way through the Mahout In Action book.
Now, I'm trying to execute a RecommenderJob, and see the following error:
Exception in thread "main" java.lang.NoClassDefFoundError:
org/apache/commons/cli2/Option
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.cli2.Option
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
... 3 more
The command I'm executing is as follows:
hadoop jar target/mahout-core-0.6-SNAPSHOT.jar
org.apache.mahout.cf.taste.hadoop.item.RecommenderJob
-Dmapred.input.dir=input/input.txt
-Dmapred.output.dir=output --usersFile input/users.txt --booleanData
This differs slightly from the command prescribed in the Mahout In Action book:
bin/hadoop jar target/mahout-core-0.4-SNAPSHOT.job
org.apache.mahout.cf.taste.hadoop.item.RecommenderJob
-Dmapred.input.dir=input/input.txt
-Dmapred.output.dir=output --usersFile input/users.txt --booleanData
Obvious differences are (i) I'm on Mahout 0.6, and (ii) I don't have a .job
file to reference, only a .jar (target/mahout-core-0.6-SNAPSHOT.jar). I don't
know if I should be referencing the .jar file in this way.
Now, I have built the jar myself, by executing:
mvn -DskipTests clean package
from the core directory of Mahout.
This appears to have worked fine, and I see the following in the core/target
directory
drwxrwxr-x 6 martin martin 4096 2012-01-18 12:24 ./
drwxrwxr-x 8 martin martin 4096 2012-01-18 12:24 ../
drwxrwxr-x 3 martin martin 4096 2012-01-18 12:24 classes/
drwxrwxr-x 4 martin martin 4096 2012-01-18 12:24 generated-sources/
-rw-rw-r-- 1 martin martin 1641278 2012-01-18 12:24 mahout-core-0.6-SNAPSHOT.jar
drwxrwxr-x 2 martin martin 4096 2012-01-18 12:24 maven-archiver/
drwxrwxr-x 3 martin martin 4096 2012-01-18 12:24 test-classes/
Notice that there is no .job file, only a .jar.
I'm not sure if the problem I'm seeing is due to the lack of a .job file, or if
it's something else that I've got wrong.
Please can you help explain why I can't run the RecommenderJob?
Many thanks,
Martin
________________________________________
This e-mail is sent on behalf of Trader Media Group Limited, Registered Office:
Auto Trader House, Cutbush Park Industrial Estate, Danehill, Lower Earley,
Reading, Berkshire, RG6 4UT(Registered in England No. 4768833). This email and
any files transmitted with it are confidential and may be legally privileged,
and intended solely for the use of the individual or entity to whom they are
addressed. If you have received this email in error please notify the sender.
This email message has been swept for the presence of computer viruses.
