...
hadoop@ubuntu:/usr/local/hadoop$ jps
2287 TaskTracker
2149 JobTracker
2349 Jps 1788 NameNode
Execute $HADOOP_HOME/bin/stop-all.sh to stop all the nodes in the cluster. This command should be issued from the node where cluster was started.
If there are any errors, examine the log files in the HADOOP_HOME/logs/ directory.
...