After I have deployed Hadoop and YARN on the local virtual machine, I execute the startup command ./sbin/start-dfs.shbut I have various error reporting problems. Here I document two common problems.
Could not resolve hostname: Name or service not known
Error message:
19/05/17 21:31:18 WARN hdfs.DFSUtil: Namenode for null remains unresolved for ID null. Check your hdfs-site.xml file to ensure namenodes are configured properly.
Starting namenodes on [jing-hadoop]
jing-hadoop: ssh: Could not resolve hostname jing-hadoop: Name or service not known
......This is because without the node name in the configuration file jing - hadoop to join the domain mapping, so I can't identify the host name.
Solutions:
vim /etc/hosts 127.0.0.1 jing-hadoop
And then you start it up again.
jing-hadoop configured in h>site.xml , and t>orresponding node IP is 127.0.0.1e>. You should modify>according to your own environment, do not copy directly.
2, Unable to load Native Hadoop Library
Perform the start - DFS. Sh , also appeared the following error:
19/05/17 21:39:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable ......
If you do not see the NameNode process after executing JPS, then this is definitely not possible.
The local classpath of Hadoop is not configured in the environment variable. The classpath is not configured in the environment variable.
vim /etc/profile export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib" source /etc/profile
Then, again start - DFS. Sh , will still be reported as errors found, but after executing the JPS, found the NameNode process and DataNode process has been started normally, so will not affect the use.
[root@localhost hadoop-2.4.1]# jps 3854 NameNode 4211 Jps 3967 DataNode 4110 SecondaryNameNode
Among them, the number of the DataNode and the IP is in $HADOOP_HOME/etc/hadoop slave file configuration, if the configure multiple IP, will start multiple DataNode process.
Read More:
- ERROR: Invalid HADOOP_COMMON_HOME
- Hadoop cluster: about course not obtain block: error reporting
- Linux common problems and Solutions
- Common problems and solutions under Linux
- OpenGL development environment configuration [vs2017] + common problems
- Some common problems in the use of vs2017
- Common problems of shadow map in OpenGL
- Common cases of ad reporting an error as unknown pin
- Common problems of Aidl cross process communication
- Common problems and basic concept knowledge of OpenGL
- mkdir: Call From hadoop102/192.168.6.102 to hadoop102:8020 failed on connection exception: java.net.
- Error reporting: attributeerror: module ‘******* has no attribute’ ******* and other problems are solved
- Some problems about startup
- Common compatibility problems of VS2010 to vs2017 projects
- Spring boot integrates Mongo to solve some common connection and permission problems. Docker compose installs Mongo
- Kylin startup error HBase common lib not found
- Problems and solutions of error reporting in using swiper in Vue
- Creating Server TCP listening socket 127.0.0.1:6379: bind: No error。。。 Solutions to problems encountered in startup
- Hadoop datanode using JPS to view the solution that can’t be started
- Error: php56w-common conflicts with php-common-5.3.3-48.el6_ 8.x86_ 64