User:Denisarnaud/Hadoop

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Overview

Bootstrapping Hadoop on Fedora for Fedora 22+.

See Also

• Hadoop on Fedora 20
• Bootstrapping Your MapReduce 2.X Programming on Fedora 20
• SIGs/bigdata/packaging/Scala / SIGs/bigdata/packaging/Sbt

Installation and Setup (as root)

Install Hadoop:

# dnf install hadoop-common hadoop-hdfs hadoop-mapreduce hadoop-mapreduce-examples hadoop-yarn maven-* xmvn*

Set the JAVA_HOME environment variable within the Hadoop configuration file (the default does not seem to work)

# vi /etc/hadoop/hadoop-env.sh

For instance, with the Open JDK, the line should read something like:

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.65-13.b17.fc23.x86_64 # On a Fedora 23

Or with Oracle Java JDK 8, the line would become:

export JAVA_HOME=/usr/java/jdk1.8.0_51

Format the name-node:

# runuser hdfs -s /bin/bash /bin/bash -c "hdfs namenode -format"

which should produce something like:

DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

15/08/16 19:09:15 INFO namenode.NameNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = myhost.mydomain/127.0.0.1
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 2.4.1
STARTUP_MSG:   classpath = /etc/hadoop:/usr/share/hadoop/common/lib/asm-tree-5.0.3.jar:[...]
STARTUP_MSG:   build = Unknown -r Unknown; compiled by 'mockbuild' on 2015-04-21T22:21Z
STARTUP_MSG:   java = 1.8.0_51
[...]
************************************************************/
15/08/16 19:09:16 INFO namenode.NameNode: registered UNIX signal handlers for [TERM, HUP, INT]
15/08/16 19:09:16 INFO namenode.NameNode: createNameNode [-format]
15/08/16 19:09:16 INFO namenode.AclConfigFlag: ACLs enabled? false
15/08/16 19:09:16 INFO namenode.FSImage: Allocated new BlockPoolId: BP-393991083-127.0.0.1-1439744956758
15/08/16 19:09:16 INFO common.Storage: Storage directory /var/lib/hadoop-hdfs/hdfs/dfs/namenode has been successfully formatted.
15/08/16 19:09:16 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 0
15/08/16 19:09:16 INFO util.ExitUtil: Exiting with status 0
15/08/16 19:09:16 INFO namenode.NameNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at myhost.mydomain/127.0.0.1
************************************************************/

Start the Hadoop services:

# systemctl start hadoop-namenode hadoop-datanode hadoop-nodemanager hadoop-resourcemanager

Check that the Hadoop services have been started:

# systemctl status hadoop-namenode hadoop-datanode hadoop-nodemanager hadoop-resourcemanager

Enable the Hadoop services permanently, in case everything went smoothly:

# systemctl enable hadoop-namenode hadoop-datanode hadoop-nodemanager hadoop-resourcemanager

Create the default HDFS directories:

# hdfs-create-dirs

Setting Up a User's Sandbox (as root)

In the following commands, build is the Unix user name:

# runuser hdfs -s /bin/bash /bin/bash -c "hadoop fs -mkdir /user/build"
# runuser hdfs -s /bin/bash /bin/bash -c "hadoop fs -chown build /user/build"

Running WordCount (as user)

For simplicity, a WordCount example is available on GitHub that you can copy:

$ git clone https://github.com/timothysc/hadoop-tests.git

Once it has downloaded you can put the example .txt file into your user location

$ cd WordCount
$ hadoop fs -put constitution.txt /user/build

Now you can build WordCount against the system installed .jars.

$ mvn-rpmbuild package 

Finally you can run:

$ hadoop jar wordcount.jar org.myorg.WordCount /user/build /user/build/output

Feel free to cat the part-0000 file to see the results.

References

Denis Arnaud's page >