For CDH 5.7.0 what is the full path to an HDFS datanode's PID file?

[#1]

For CDH 5.7.0 what is the full path to an HDFS datanode's PID file?

[#2]

Could you check your /tmp . 

[#3]

I did, it's not in /tmp.

[#4]

check the status of datanode dameon in that host

meantime the pfile should be in 

/var/run/hadoop-hdfs/hadoop-hdfs-datanode.pid

[#5]

I can get the PID via a "pgrep -fa datanode" but would prefer to find where
it writes its PID to a file.

[#6]

Check the below location for datanode pid file 

/var/run/hadoop-hdfs/

[#7]

@JeffKubina,

Since the supervisor starts CM managed processes, there is no PID file for the processes it starts.

Short answer:  there is no PID file.

-Ben

[#8]

So what is the recommended way of getting the datanodes PID?

[#9]

@JeffKubina,

While there are a number of ways to get the PID (like ps aux |grep ....), this is one I just thought up:

/usr/lib64/cmf/agent/build/env/bin/supervisorctl -c /var/run/cloudera-scm-agent/supervisor/supervisord.conf pid `ls -lrt /var/run/cloudera-scm-agent/process/ | awk '{print $9}' |grep DATANODE| tail -1`

What it does is run supervisor's client using the Cloudera Manager sueprvisord.conf file to retrieve a pid file.  The backticks execute a command to get the most recent process directory to pass into the "pid" command of supervisorctl.  You can see the process names and statuses using the following:

/usr/lib64/cmf/agent/build/env/bin/supervisorctl -c /var/run/cloudera-scm-agent/supervisor/supervisord.conf status

-Ben

[#10 · Accepted solution]

@JeffKubina

Oops, that was overkill... forgot that supervisorctl status output has the PID column already...  So, you can run:

/usr/lib64/cmf/agent/build/env/bin/supervisorctl -c /var/run/cloudera-scm-agent/supervisor/supervisord.conf status

The PID will be the 4th column.

-Ben