Oozie & Hugh: Why am I getting a permission denied error when playing an oozie workflow?

I am new to Hue and Oozie. I have installed a Cloudera 5 cluster with Hue. I logged into Hue as Thomas, and created an Oozie dashboard that only runs the hive script. But, when I launch the toolbar, I get the following error stating that it is not possible to write to inode / tmp / hadoop-yarn:

2015-06-12 13:36:01,014  WARN ActionStartXCommand:523 - SERVER[cdh-master] USER[thomas] GROUP[-] TOKEN[] APP[My_Workflow] JOB[0000000-150612132534763-oozie-oozi-W] ACTION[0000000-150612132534763-oozie-oozi-W@hive2-3283] Error starting action [hive2-3283]. ErrorType [TRANSIENT], ErrorCode [JA009], Message [JA009: Permission denied: user=thomas, access=WRITE, inode="/tmp/hadoop-yarn":yarn:hadoop:drwxr-xr-x
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkFsPermission(DefaultAuthorizationProvider.java:257)
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:238)
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:216)

      

        
        
        
      

    

I did some search on stackoverflow and so and already add the following lines:

• in HADOOP_HOME / hadoop-conf / core-site.xml: <property> <name>hadoop.proxyuser.thomas.groups</name> <value>*</value> </property> <property> <name>hadoop.proxyuser.thomas.hosts</name> <value>*</value> </property>
  
  
• In OOZIE_HOME / oozie-site.xml: <property> <name>oozie.service.ProxyUserService.proxyuser.thomas.hosts</name> <value>*</value> </property> <property> <name>oozie.service.ProxyUserService.proxyuser.thomas.groups</name> <value>*</value> </property>
  
  

It doesn't seem to have any effects. Anyone have an idea?

thank