How to Set Up Hadoop Multi-Node Cluster on CentOS 7/6

By RahulJuly 22, 20134 Mins Read

The Apache Hadoop software library is a framework that allows for the distributed processing of large data sets across clusters of computers using simple programming models.

Our earlier article about hadoop was describing to how to setup single node cluster. This article will help you for step by step installing and configuring Hadoop Multi-Node Cluster on CentOS/RHEL 6.

Setup Details:

Hadoop Master: 192.168.1.15 ( hadoop-master )
Hadoop Slave : 192.168.1.16 ( hadoop-slave-1 )
Hadoop Slave : 192.168.1.17 ( hadoop-slave-2 )

Step 1. Install Java

Before installing hadoop make sure you have java installed on all nodes of hadoop cluster systems.

# java -version

java version "1.7.0_75"
Java(TM) SE Runtime Environment (build 1.7.0_75-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.75-b04, mixed mode)

If you do not have java installed use following article to install Java.

Steps to install JAVA 7 on CentOS/RHEL 7/6/5

Step 2. Create User Account

Create a system user account on both master and slave systems to use for hadoop installation

# useradd hadoop
# passwd hadoop

Changing password for user hadoop.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

Step 3: Add FQDN Mapping

Edit /etc/hosts file on all master and slave servers and add following entries.

# vim /etc/hosts

192.168.1.15 hadoop-master
192.168.1.16 hadoop-slave-1
192.168.1.17 hadoop-slave-2

Step 4. Configuring Key Based Login

It’s required to set up hadoop user to ssh itself without password. Use following commands to configure auto login between all hadoop cluster servers..

# su - hadoop
$ ssh-keygen -t rsa
$ ssh-copy-id -i ~/.ssh/id_rsa.pub hadoop@hadoop-master
$ ssh-copy-id -i ~/.ssh/id_rsa.pub hadoop@hadoop-slave-1
$ ssh-copy-id -i ~/.ssh/id_rsa.pub hadoop@hadoop-slave-2
$ chmod 0600 ~/.ssh/authorized_keys
$ exit

Step 5. Download and Extract Hadoop Source

Download hadoop latest available version from its official site at hadoop-master server only.

# mkdir /opt/hadoop
# cd /opt/hadoop/
# wget http://apache.mesi.com.ar/hadoop/common/hadoop-1.2.0/hadoop-1.2.0.tar.gz
# tar -xzf hadoop-1.2.0.tar.gz
# mv hadoop-1.2.0 hadoop
# chown -R hadoop /opt/hadoop
# cd /opt/hadoop/hadoop/

Step 6: Configure Hadoop

First edit hadoop configuration files and make following changes.
6.1 Edit core-site.xml

# vim conf/core-site.xml

#Add the following inside the configuration tag
<property>
    <name>fs.default.name</name>
    <value>hdfs://hadoop-master:9000/</value>
</property>
<property>
    <name>dfs.permissions</name>
    <value>false</value>
</property>

6.2 Edit hdfs-site.xml

# vim conf/hdfs-site.xml

# Add the following inside the configuration tag
<property>
	<name>dfs.data.dir</name>
	<value>/opt/hadoop/hadoop/dfs/name/data</value>
	<final>true</final>
</property>
<property>
	<name>dfs.name.dir</name>
	<value>/opt/hadoop/hadoop/dfs/name</value>
	<final>true</final>
</property>
<property>
	<name>dfs.replication</name>
	<value>1</value>
</property>

6.3 Edit mapred-site.xml

# vim conf/mapred-site.xml

# Add the following inside the configuration tag
<property>
        <name>mapred.job.tracker</name>
	<value>hadoop-master:9001</value>
</property>

6.4 Edit hadoop-env.sh

# vim conf/hadoop-env.sh

export JAVA_HOME=/opt/jdk1.7.0_75
export HADOOP_OPTS=-Djava.net.preferIPv4Stack=true
export HADOOP_CONF_DIR=/opt/hadoop/hadoop/conf

Set JAVA_HOME path as per your system configuration for java.

Step 7: Copy Hadoop Source to Slave Servers

After updating above configuration, we need to copy the source files to all slaves servers.

# su - hadoop
$ cd /opt/hadoop
$ scp -r hadoop hadoop-slave-1:/opt/hadoop
$ scp -r hadoop hadoop-slave-2:/opt/hadoop

Step 8: Configure Hadoop on Master Server Only

Go to hadoop source folder on hadoop-master and do following settings.

# su - hadoop
$ cd /opt/hadoop/hadoop

$ vim conf/masters

hadoop-master

$ vim conf/slaves

hadoop-slave-1
hadoop-slave-2

Format Name Node on Hadoop Master only

# su - hadoop
$ cd /opt/hadoop/hadoop
$ bin/hadoop namenode -format

13/07/13 10:58:07 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = hadoop-master/192.168.1.15
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 1.2.0
STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1479473; compiled by 'hortonfo' on Mon May  6 06:59:37 UTC 2013
STARTUP_MSG:   java = 1.7.0_25
************************************************************/
13/07/13 10:58:08 INFO util.GSet: Computing capacity for map BlocksMap
13/07/13 10:58:08 INFO util.GSet: VM type       = 32-bit
13/07/13 10:58:08 INFO util.GSet: 2.0% max memory = 1013645312
13/07/13 10:58:08 INFO util.GSet: capacity      = 2^22 = 4194304 entries
13/07/13 10:58:08 INFO util.GSet: recommended=4194304, actual=4194304
13/07/13 10:58:08 INFO namenode.FSNamesystem: fsOwner=hadoop
13/07/13 10:58:08 INFO namenode.FSNamesystem: supergroup=supergroup
13/07/13 10:58:08 INFO namenode.FSNamesystem: isPermissionEnabled=true
13/07/13 10:58:08 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
13/07/13 10:58:08 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
13/07/13 10:58:08 INFO namenode.FSEditLog: dfs.namenode.edits.toleration.length = 0
13/07/13 10:58:08 INFO namenode.NameNode: Caching file names occuring more than 10 times
13/07/13 10:58:08 INFO common.Storage: Image file of size 112 saved in 0 seconds.
13/07/13 10:58:08 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/opt/hadoop/hadoop/dfs/name/current/edits
13/07/13 10:58:08 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/opt/hadoop/hadoop/dfs/name/current/edits
13/07/13 10:58:08 INFO common.Storage: Storage directory /opt/hadoop/hadoop/dfs/name has been successfully formatted.
13/07/13 10:58:08 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at hadoop-master/192.168.1.15
************************************************************/

Step 9: Start Hadoop Services

Use the following command to start all hadoop services on Hadoop-Master

$ bin/start-all.sh

View 23 Comments

23 Comments

isak on April 28, 2020 8:02 pm
hi i take these mistake. what is the reason?
WARNING: Use of this script to execute namenode is deprecated.
WARNING: Attempting to execute replacement “hdfs namenode” instead.
WARNING: /opt/hadoop/hadoop/logs does not exist. Creating.
Error: Could not find or load main class Djava.net.preferIPv4Stack=true
Reply
aruur on July 25, 2019 8:53 pm
I cant see “Step 8: Configure Hadoop on Master Server Only” masters file and slaves file..
I use centos7 and hadoop 3.2.0
Why ??
thank u brother..
Reply
Anandachetan on June 11, 2018 3:24 am
Excellent article.
Reply
Selvaesakki on December 8, 2017 5:05 pm
Hi Rahul,
Am facing below issue,Master Started but Slaves not started..
bin/start-all.sh
namenode running as process 2767. Stop it first.
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-master: secondarynamenode running as process 2916. Stop it first.
jobtracker running as process 2996. Stop it first.
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
Reply
Selvaesakki on December 7, 2017 10:18 pm
Hi Rahul,
Am facing below issue,pls guide me
bin/start-all.sh
starting namenode, logging to /opt/hadoop/hadoop/libexec/../logs/hadoop-hadoop-namenode-ip-10-0-0-59.out
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-master: starting secondarynamenode, logging to /opt/hadoop/hadoop/libexec/../logs/hadoop-hadoop-secondarynamenode-ip-10-0-0-59.out
starting jobtracker, logging to /opt/hadoop/hadoop/libexec/../logs/hadoop-hadoop-jobtracker-ip-10-0-0-59.out
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
[hadoop@ip-10-0-0-59 hadoop]$ bin/stop-all.sh
stopping jobtracker
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
stopping namenode
hadoop-slave-2: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-2: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-slave-1: bash: line 0: cd: /opt/hadoop/hadoop/libexec/..: No such file or directory
hadoop-slave-1: bash: /opt/hadoop/hadoop/bin/hadoop-daemon.sh: No such file or directory
hadoop-master: stopping secondarynamenode
By Selva
Reply
Dinakar N K on October 13, 2017 7:40 am
Hi Mr Rahul,
Could you kindly clarify me can we share hadoop single node cluster to multiple users a (group of 60). If so could you kindly help me for the same
Reply
Sam on December 22, 2016 7:48 am
Hi Rahul, great article but I got stuck on step #7. I run the scp commands, the error I got was “Access denied”. I then decided to give hadoop user on each node an administrator/root privilege. I then run the command again just to receive the follwoing error message :
[hadoop@hmaster hadoop]$ scp -r hadoop hadoop-slave-2:/opt/hadoop
hadoop@hadoop-slave-2’s password:
hadoop: No such file or directory
What do you I might have done wrong? Thanks for your help in advance.
Reply
Prateek Harsh on July 21, 2016 4:04 pm
Hi Rahul,
I have done whatever you have suggested and everything is going fine except last step to start hadoop in master after giving command start-all.sh getting error ” -bash : start-all.sh: command not found”. Even though i have given hadoop path in .bashrc file.
Reply
inner on July 19, 2016 11:37 pm
If my comments will be shown here I will explain what I did to fix my problem. It is all fixed and working now!
Reply
inner on July 19, 2016 8:14 pm
Finally, I have got them working now. They all are alive now, but yet I can’t put any files into hdfs:
[hadoop@namenode1 hadoop]$ ./bin/hdfs dfs -put /home/hadoop/node_setup /names/node_setup
16/07/19 21:11:42 INFO hdfs.DFSClient: Exception in createBlockOutputStream
java.net.NoRouteToHostException: No route to host
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.hdfs.DFSOutputStream.createSocketForPipeline(DFSOutputStream.java:1537)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:1313)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1266)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449)
16/07/19 21:11:42 INFO hdfs.DFSClient: Abandoning BP-1606715859-192.168.0.13-1468886056606:blk_1073741825_1001
16/07/19 21:11:42 INFO hdfs.DFSClient: Excluding datanode DatanodeInfoWithStorage[192.168.0.15:50010,DS-bb00767f-26f0-428f-b563-30c2b712fd5f,DISK]
16/07/19 21:11:42 INFO hdfs.DFSClient: Exception in createBlockOutputStream
java.net.NoRouteToHostException: No route to host
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.hdfs.DFSOutputStream.createSocketForPipeline(DFSOutputStream.java:1537)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:1313)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1266)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449)
16/07/19 21:11:42 INFO hdfs.DFSClient: Abandoning BP-1606715859-192.168.0.13-1468886056606:blk_1073741826_1002
16/07/19 21:11:42 INFO hdfs.DFSClient: Excluding datanode DatanodeInfoWithStorage[192.168.0.16:50010,DS-c58b5570-9cd7-491b-823f-d08a67482a0f,DISK]
16/07/19 21:11:42 INFO hdfs.DFSClient: Exception in createBlockOutputStream
java.net.NoRouteToHostException: No route to host
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:739)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.hdfs.DFSOutputStream.createSocketForPipeline(DFSOutputStream.java:1537)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream(DFSOutputStream.java:1313)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1266)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449)
16/07/19 21:11:42 INFO hdfs.DFSClient: Abandoning BP-1606715859-192.168.0.13-1468886056606:blk_1073741827_1003
16/07/19 21:11:42 INFO hdfs.DFSClient: Excluding datanode DatanodeInfoWithStorage[192.168.0.14:50010,DS-757164da-1541-43ff-9271-379abb45f774,DISK]
16/07/19 21:11:42 WARN hdfs.DFSClient: DataStreamer Exception
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /names/node_setup._COPYING_ could only be replicated to 0 nodes instead of minReplication (=1). There are 3 datanode(s) running and 3 node(s) are excluded in this operation.
at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget4NewBlock(BlockManager.java:1547)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getNewBlockTargets(FSNamesystem.java:3107)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:3031)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:724)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:492)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)
at org.apache.hadoop.ipc.Client.call(Client.java:1475)
at org.apache.hadoop.ipc.Client.call(Client.java:1412)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
at com.sun.proxy.$Proxy9.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:418)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy10.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.locateFollowingBlock(DFSOutputStream.java:1459)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1255)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:449)
put: File /names/node_setup._COPYING_ could only be replicated to 0 nodes instead of minReplication (=1). There are 3 datanode(s) running and 3 node(s) are excluded in this operation.
[hadoop@namenode1 hadoop]$
Reply
inner on July 19, 2016 7:11 pm
Thanks for the guide! Now, I am having a problem after I incorrectly turned off the cluster of 3 datanodes. All of them now are dead, it is shown after executing a command:
./bin/hdfs dfsadmin -refreshNodes
Configured Capacity: 0 (0 B)
Present Capacity: 0 (0 B)
DFS Remaining: 0 (0 B)
DFS Used: 0 (0 B)
DFS Used%: NaN%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0
————————————————-
Dead datanodes (3):
Name: 192.168.0.15:50010 (datanode2)
Hostname: datanode2
Decommission Status : Normal
Configured Capacity: 0 (0 B)
DFS Used: 0 (0 B)
Non DFS Used: 0 (0 B)
DFS Remaining: 0 (0 B)
DFS Used%: 100.00%
DFS Remaining%: 0.00%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 0
Last contact: Thu Jan 01 01:00:00 GMT 1970
Name: 192.168.0.14:50010 (datanode1)
Hostname: datanode1
Decommission Status : Normal
Configured Capacity: 0 (0 B)
DFS Used: 0 (0 B)
Non DFS Used: 0 (0 B)
DFS Remaining: 0 (0 B)
DFS Used%: 100.00%
DFS Remaining%: 0.00%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 0
Last contact: Thu Jan 01 01:00:00 GMT 1970
Name: 192.168.0.16:50010 (datanode3)
Hostname: datanode3
Decommission Status : Normal
Configured Capacity: 0 (0 B)
DFS Used: 0 (0 B)
Non DFS Used: 0 (0 B)
DFS Remaining: 0 (0 B)
DFS Used%: 100.00%
DFS Remaining%: 0.00%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 0
Last contact: Thu Jan 01 01:00:00 GMT 1970
How do I recover the datanodes?
What I have already tried is to turn off/on again, -format command, -refreshNodes command, included all datanodes in the permitted hosts file, nothing helps.
There’s got to be a way restoring these datanodes and running them again..
Reply
Shankar on June 26, 2015 7:18 am
Hi,
Nice Guide, I have some problem, while starting all node except datanode is not showing in jps.
What is the issue?
Please help.
Thanks in Advance
Shankar D
Reply
- Rahul on June 26, 2015 9:36 am
  Hi Shankar,
  Please check log files and let us know any any error is generating there.
  Reply
  - Punit Bansal on May 8, 2017 5:01 am
    Hi Rahul,
    I have installed the hadoop in ubuntu 16.04 but i am not able to install the hadoop in CentOS.
    In ubuntu i am able to set the Interfaces, hostname and hosts but not able to set the these things in centos.
    Please share the some steps.
    Thanks
    Punit
    Reply
Alex on February 19, 2015 10:31 am
Hi Rahul,
nice guide! I have a problem running the step number 4.
it got this error:
it is impossible to create .ssh dir
which permission should have hadoop user? in which groups should be menber?
thank you in advance for your time
Alex
Reply
Karthik on September 1, 2014 10:35 am
Hi Rahul,
I had followed your steps for cluster installation and i successfully done it with namenode & one datanode, now i have some small doubts about how to load data into datanode directly from servers and how to get it into HDFS. plz help me with some suggestions.
And can i install hive on name node by following your HIVE article now
Reply
Singh on March 13, 2014 8:43 pm
Hey Rahul,
That was awesome clear instrauction. I was able to do this thing with little twicks for java. But I would say great article. Thanks
Reply
Kiran on February 15, 2014 4:30 pm
Hi Rahul,
Could u send me the roles & responsibilites of Hadoop Admin and tips for Admin ?
I would need to put in my CV ..
Pls kindly help me .
Reply
Alex on January 21, 2014 2:48 pm
It is cool, what you wrote, but…. 1. Where I could verify what hadoop working? I couldn’t find any logs on slave. 2. Any examples how it is working? Like put any web sites or what?
Thanks anyway, it is working on the master.
Reply
Bill on November 11, 2013 9:05 am
Thank you Rahul!
This is excellent! Simple and clear instructions, helped me a lot!
Reply
savitha on September 14, 2013 5:16 am
Hi Rahul
I found this article useful for my work, Thank You. I hve already created a single node cluster and i am planning to do multi node, is it possible to do it in 2 laptop with same configuration and memory. if so wat are the requirements needed for hardware settings like switches,cables.
Reply
venkatrama rao on August 13, 2013 5:00 pm
Hi
Thanks Rahul for your nice and simple artilcle,
am followed all the steps as mentioned but my data nodes (slvae1 & slave2) are not starting
it worked in single node installation..
i dont where i messedup.., passwordless ssh is working fine and when am trying to start the services in slave1 it asking for password of hadoop@localhost: insteadof either hadoop@name-node or hadoop@slave1. why pls help me
Thanks in advance
Venaktrama rao
Reply
- Rahul on August 14, 2013 7:52 am
  Hi Venaktrama,
  You only need to start service at master server ( Step #9 ). and watch the logs on slave servers.
  Reply