Hadoop

Hadoop is a Java-based programming framework that supports the processing and storage of extremely large datasets on a cluster of inexpensive machines. It was the first major open source project in the big data playing field and is sponsored by the Apache Software Foundation. Hadoop is comprised of four main layers:

1. Hadoop Common is the collection of utilities and libraries that support other Hadoop modules.
2. HDFS, which stands for Hadoop Distributed File System, is responsible for persisting data to disk.
3. YARN, short for Yet Another Resource Negotiator, is the "operating system" for HDFS.
4. MapReduce is the original processing model for Hadoop clusters. It distributes work within the cluster or map, then organizes and reduces the results from the nodes into a response to a query. Many other processing models are available for the 3.x version of Hadoop

Configuration

mkdir -p /home/hadoop/hdfs/{datanode,namenode}/
sudo tee -a $HADOOP_HOME/etc/hadoop/core-site.xml >/dev/null <<EOF
<configuration>
    <property>
        <name>hadoop.tmp.dir</name>
        <value>/home/hadoop/tmp</value>
    </property>
    <property>
        <name>fs.default.name</name>
        <value>hdfs://0.0.0.0:9000</value>
        <description>The default file system URI</description>
    </property>
</configuration>
EOF

---

mkdir -p /home/hadoop/hdfs/{datanode,namenode}
sudo tee -a $HADOOP_HOME/etc/hadoop/hdfs-site.xml >/dev/null <<EOF
<configuration>
    <property>
      <name>dfs.replication</name>
      <value>1</value>
    </property>
    <property>
      <name>dfs.namenode.name.dir</name>
      <value>/home/hadoop/hdfs/namenode/</value>
    </property>
    <property>
      <name>dfs.datanode.data.dir</name>
      <value>/home/hadoop/hdfs/datanode/</value>
    </property>
</configuration>
EOF

---

sudo tee -a $HADOOP_HOME/etc/hadoop/mapred-site.xml >/dev/null <<EOF
<configuration>
    <property>
        <name>mapreduce.framework.name</name>
        <value>yarn</value>
    </property>
</configuration>
EOF

---

sudo tee -a $HADOOP_HOME/etc/hadoop/yarn-site.xml >/dev/null <<EOF
<configuration>
    <property>
        <name>yarn.nodemanager.aux-services</name>
        <value>mapreduce_shuffle</value>
    </property>
</configuration>
EOF

Knowledge

ssh-keygen -b 4096 -t rsa -f ~/.ssh/id_rsa -q -N "[email protected]" readlink -f /usr/bin/java | sed "s:bin/java::" sudo apt-get install pdsh sudo apt-get install ssh
su -h hadoop hdfs namenode -format sudo -u haddop -H sh -c "whoami; echo ${HOME}" sh $HADOOP_HOME/sbin/start-dfs.sh http://127.0.0.1:9870 sh $HADOOP_HOME/sbin/start-yarn.sh http://127.0.0.1:8088
sudo apt dist-upgrade sudo do-release-upgrade sudo apt --fix-broken install sudo apt install ubuntu-desktop	[Service] User=hadoop Group=hadoop Type=forking SuccessExitStatus=143

References

Hadoop » Install Standalone Mode on Ubuntu 20.04 Hadoop » Install & Configure on Ubuntu 20.04 Hadoop » Big Data Concepts & Terminology Hadoop » Setting up a Single Node Cluster Hadoop » Install as a Daemon Hadoop » Download » Archive Hadoop » Download » Current Hadoop » Download » Stable Hadoop » An Introduction Hadoop » Docs » Stable	Hadoop » hadoop-mapreduce-client-core/mapred-default.xml Hadoop » hadoop-yarn-common/yarn-default.xml Hadoop » Running Spark on Top of a Hadoop YARN Hadoop » hadoop-hdfs/hdfs-default.xml Hadoop » Java Versions VS Code on iPad Pro Machine Learning Jupyter Spark NLP	Hadoop » Firewall Transparency Hadoop » Hortonworks
Bash » Difference between /opt and /usr/local Bash » Switch user & execute remaining script Difference between sudo user vs. root user Create a Sudo User & Manage Access Bash » Non-interactive ssh-keygen Bash » Switch user & execute script Bash » Add a user if it doesn't exist SSH Connection Hang Forever