Comments on: How to Install and Configure Apache Hadoop on a Single Node in CentOS 7

By: James Ren

James Ren — Sat, 02 Mar 2019 22:41:25 +0000

dfs.data.dir and dfs.name.dir are wrong. It should be:

dfs.datanode.data.dir
dfs.namenode.name.dir

By: edwin rincon molina

edwin rincon molina — Fri, 18 Jan 2019 21:27:14 +0000

Hi everybody

I install the Hadoop but now i try to upload file a get error Permission denied: user=dr.who, access=WRITE, inode=”/”:hadoop:supergroup:drwxr-xr-x

By: Damini

Damini — Thu, 22 Nov 2018 05:32:27 +0000

Following this guide while doing this step – ssh-copy-id master.

I am getting errors:

/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed — if you are prompted now it is to install the new keys
##################################################################################
NOTE: You have accessed a system owned by FIWARE Lab. You must have authorisation
before using it, and your use will be strictly limited to that indicated in the
authorisation.
Unauthorised access to this system or improper use of the same is prohibited and
is against the FIWARE Terms & Conditions Policy and the legislation in force. The
use of this system may be monitored.
#################################################################################

Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

Please help me out.

By: Roshan Nagpure

Roshan Nagpure — Fri, 07 Sep 2018 16:16:13 +0000

I am not able to start yarn, can please help me out here:

[hadoop@master ~]$ start-yarn.sh

starting yarn daemons
starting resourcemanager, logging to /opt/hadoop/logs/yarn-hadoop-resourcemanager-master.out
hadoop@192.168.25.129's password: hadoop@master.hadoop.com's password: 
192.168.25.129: starting nodemanager, logging to /opt/hadoop/logs/yarn-hadoop-nodemanager-master.out


hadoop@master.hadoop.com's password: master.hadoop.com: Permission denied, please try again.

hadoop@master.hadoop.com's password: master.hadoop.com: Permission denied, please try again.

master.hadoop.com: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).

By: srd

srd — Mon, 02 Jul 2018 10:53:16 +0000

Step 5: Start and Test Hadoop Cluster After entering this command i am getting following error. Please help me to resolved this issue.

[hadoop@master ~]$ start-dfs.sh

Sample Error

18/07/02 15:41:05 ERROR conf.Configuration: error parsing conf mapred-site.xml
com.ctc.wstx.exc.WstxParsingException: Illegal processing instruction target ("xml"); 
xml (case insensitive) is reserved by the specs.
 at [row,col,system-id]: [2,5,"file:/opt/hadoop/etc/hadoop/mapred-site.xml"]
	at com.ctc.wstx.sr.StreamScanner.constructWfcException(StreamScanner.java:621)
	at com.ctc.wstx.sr.StreamScanner.throwParseError(StreamScanner.java:491)
	at com.ctc.wstx.sr.BasicStreamReader.readPIPrimary(BasicStreamReader.java:4019)
	at com.ctc.wstx.sr.BasicStreamReader.nextFromProlog(BasicStreamReader.java:2141)
	at com.ctc.wstx.sr.BasicStreamReader.next(BasicStreamReader.java:1181)
	at org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:2799)
	at org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:2728)
	at org.apache.hadoop.conf.Configuration.getProps(Configuration.java:2605)
	at org.apache.hadoop.conf.Configuration.get(Configuration.java:1103)
	at org.apache.hadoop.conf.Configuration.getTrimmed(Configuration.java:1157)
	at org.apache.hadoop.conf.Configuration.getLong(Configuration.java:1434)
	at org.apache.hadoop.security.Groups.(Groups.java:112)
	at org.apache.hadoop.security.Groups.(Groups.java:101)
	at org.apache.hadoop.security.Groups.getUserToGroupsMappingService(Groups.java:449)
	at org.apache.hadoop.security.UserGroupInformation.initialize(UserGroupInformation.java:323)
	at org.apache.hadoop.security.UserGroupInformation.ensureInitialized(UserGroupInformation.java:290)
	at org.apache.hadoop.security.UserGroupInformation.loginUserFromSubject(UserGroupInformation.java:850)
	at org.apache.hadoop.security.UserGroupInformation.getLoginUser(UserGroupInformation.java:820)
	at org.apache.hadoop.security.UserGroupInformation.getCurrentUser(UserGroupInformation.java:689)
	at org.apache.hadoop.hdfs.tools.GetConf.run(GetConf.java:315)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:90)
	at org.apache.hadoop.hdfs.tools.GetConf.main(GetConf.java:332)
Exception in thread "main" java.lang.RuntimeException: com.ctc.wstx.exc.WstxParsingException: 
Illegal processing instruction target ("xml"); xml (case insensitive) is reserved by the specs.
 at [row,col,system-id]: [2,5,"file:/opt/hadoop/etc/hadoop/mapred-site.xml"]
....