问题
I am trying to install hadoop on ubuntu 16.04 but while starting the hadoop it will give me following error
localhost: ERROR: Cannot set priority of datanode process 32156.
Starting secondary namenodes [it-OptiPlex-3020]
2017-09-18 21:13:48,343 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting resourcemanager
Starting nodemanagers
Please someone tell me why i am getting this error ? Thanks in advance.
回答1:
I have run into the same error when installing Hadoop 3.0.0-RC0. My situation was all services starting successfully except Datanode.
I found that some configs in hadoop-env.sh weren't correct in version 3.0.0-RC0, but were correct in version 2.x.
I ended up replacing my hadoop-env.sh with the official one and set JAVA_HOME and HADOOP_HOME. Now, Datanodes is working fine.
回答2:
I suggest you take a look at your hadoop datanode logs.
This is probably a configuration issue.
In my case, folders configured in dfs.datanode.data.dir didn't exist and an exception was thrown and written to log.
回答3:
I had to deal with the same issue and kept getting the following exception:
Starting namenodes on [localhost]
Starting datanodes
localhost: ERROR: Cannot set priority of datanode process 8944
Starting secondary namenodes [MBPRO-0100.local]
2019-07-22 09:56:53,020 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
As others have mentioned, you need to first make sure that all path parameters are set correctly which is what I checked first. Then followed these steps to solve the issue:
1- Stop dfs service and format hdfs:
sbin/stop-dfs.sh
sudo bin/hdfs namenode -format
2- Change permissions for the hadoop temp directory:
sudo chmod -R 777 /usr/local/Cellar/hadoop/hdfs/tmp
3- Start service again:
sbin/start-dfs.sh
Good luck
回答4:
Faced the same issue, flushed the folders: datanode & namenode.
I have put the folders in /hadoop_store/hdfs/namenode & /hadoop_store/hdfs/datanode
Post deleting the folders, recreate and then run the command hdfs namenode -format
Start the hadoop:
After the fix the logs look good:
Starting namenodes on [localhost]
Starting datanodes
Starting secondary namenodes [ip]
2019-02-11 09:41:30,426 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
jps:
21857 NodeManager
21697 ResourceManager
21026 NameNode
22326 Jps
21207 DataNode
21435 SecondaryNameNode
来源：https://stackoverflow.com/questions/46283634/localhost-error-cannot-set-priority-of-datanode-process-32156