I am using CDH 4.4 and trying to run "HelloWorld" java action in oozie (Web UI). I get "java.lang.ClassNotFoundException: Class HelloWorld not found". I have uploaded the jar in the workflow`s workspace. Is there a place where i have to set the classpath? Or is there anything else that i am missing? Configuration: Name Value hue-id-w 22 jobTracker localhost.localdomain:8021 nameNode hdfs://localhost.localdomain:8020 oozie.use.system.libpath true oozie.wf.application.path hdfs://localhost.localdomain:8020/user/hue/oozie/workspaces/_cloudera_-oozie-22-1389296910.99 user.name cloudera   Definition: "<workflow-app name="WF22" xmlns="uri:oozie:workflow:0.4">     <start to="GBB12"/>     <action name="GBB12">         <java>             <job-tracker>${jobTracker}</job-tracker>             <name-node>${nameNode}</name-node>             <main-class>HelloWorld</main-class>             <arg>er</arg>         </java>         <ok to="end"/>         <error to="kill"/>     </action>     <kill name="kill">         <message>Action failed, error message[${wf:errorMessage(wf:lastErrorNode())}]</message>     </kill>     <end name="end"/> </workflow-app>"   ... View more