Is there any way to check which Hadoop daemons are running

Question

How can I check if Hadoop daemons are running? Is there any command?

I just want to check if my Hadoop is setup correctly or not. So, I want to check if namemonode/datanode/jobtracker/tasktracker are running on my machine.

Is there any way to check it without looking into logs or using ps(on Centos)?

Answer 1

To check Hadoop daemons are running or not, what you can do is just run the jps command in the shell.

You just have to type 'jps' (make sure JDK is installed in your system). It lists all the running java processes and will list out the Hadoop daemons that are running.

Alternatively, you can use the following command:

ps -ef | grep hadoop | grep -P  'namenode|datanode|tasktracker|jobtracker'

and 

./hadoop dfsadmin -report

You can also check if the daemons are running or not through their web ui.

Learn more about Big Data Architect and its concepts from the Data architect course.

Answer 2

jps

will show all the running daemons

Answer 3

ps -ef | grep hadoop | grep -P  'namenode|datanode|tasktracker|jobtracker'

./hadoop dfsadmin -report

Answer 4

You can use the web interface to check which daemons are running

Answer 5

Here's another way:

sudo -u hdfs hdfs dfsadmin -report

Answer 6

Not a good method but a possible one:

for service in /etc/init.d/hadoop-hdfs-*; do $service status; done;

Answer 7

hdfs dfsadmin -report

Answer 8

use jps command, It will show all the running java process with their name.

Comments

But in Screenshot datanode, jobtracker etc., are not shown. I want to check if those services are running or not.

Answer 9

run thecommand jps