question Re: What is hadoop_secure_dn_pid under /var/run/hadoop/hdfs directory? in Archives of Support Questions (Read Only)

What is hadoop_secure_dn_pid under /var/run/hadoop/hdfs directory?

ashwini_ash_pat — Sun, 09 Jul 2017 13:42:35 GMT

Re: What is hadoop_secure_dn_pid under /var/run/hadoop/hdfs directory?

jsensharma — Sun, 09 Jul 2017 14:00:59 GMT

In a kerberized environment the DataNode does not use the RPC framework of Hadoop, DataNode must authenticate itself by using privileged ports which are specified by dfs.datanode.address and dfs.datanode.http.address. There you will see this PID is being used. "/var/run/hadoop/hdfs/hadoop_secure_dn.pid"

Example:

jsvc.exec -Dproc_datanode -outfile /var/log/hadoop/hdfs/jsvc.out -errfile /var/log/hadoop/hdfs/jsvc.err -pidfile /var/run/hadoop/hdfs/hadoop_secure_dn.pid

You can find the "HADOOP_SECURE_DN_PID" parameter info inside the "/usr/hdp/current/hadoop-hdfs-datanode/bin/hdfs.distro" file.

Please see: https://community.hortonworks.com/articles/90673/why-datanodes-have-two-processes-on-a-kerberized-c.html

Re: What is hadoop_secure_dn_pid under /var/run/hadoop/hdfs directory?

ashwini_ash_pat — Sun, 09 Jul 2017 20:11:13 GMT

Thanks@Jay SenSharma ...i understood the parameter..but i'm facing one problem with this. I had set the permission rights for both of the pid but when i checked this few days back permissions was changed..i set that back and today again i found it has changed.So can anybody help me with this..what will be the cause to change this parameter's permissions frequently?