According to popular articles, Hadoop uses the concept of parallelism to upload the split data while fulfilling Velocity problem.

Embarking on the journey to configure Hadoop involves meticulous steps to ensure seamless operation. Here’s a detailed guide divided into three essential phases: configuring the NameNode, DataNode, and the Client.

Setting Up Hadoop: A Comprehensive Guide

Embarking on the journey to configure Hadoop involves meticulous steps to ensure seamless operation. Here’s a detailed guide divided into three essential phases: configuring the NameNode, DataNode, and the Client.

Phase 1: NameNode Configuration

1. 1 Establish the “nn” Directory: Creating a dedicated directory at the root (“/”) named “nn” is the initial step. This directory serves as the repository for metadata and crucial information related to the NameNode.

mkdir /nn        

1. 2 Configure “hdfs-site.xml” for NameNode: Define the storage location for the NameNode data in the “/nn” directory by updating the Hadoop configuration in the “hdfs-site.xml” file.

echo "<configuration><property><name>dfs.namenode.name.dir</name><value>/nn</value></property></configuration>" > $HADOOP_HOME/etc/hadoop/hdfs-site.xml        

1. 3 Configure “core-site.xml” for NameNode: Specify the default file system as HDFS and set the NameNode address in the “core-site.xml” configuration.

echo "<configuration><property><name>fs.defaultFS</name><value>hdfs://localhost:9000</value></property></configuration>" > $HADOOP_HOME/etc/hadoop/core-site.xml        

1.4 Format NameNode: Initialize Hadoop Distributed File System (HDFS) and format the NameNode to prepare for service initiation.

hdfs namenode -format        

1.5 Start NameNode: Initiate the Hadoop Distributed File System, including the NameNode, using the “start-dfs.sh” script.

start-dfs.sh        

These meticulous steps ensure the proper configuration of the NameNode, a pivotal component in Hadoop’s distributed file system.

Phase 2: DataNode Configuration

2.1 Create the “dn” Directory: Similar to the NameNode, establish a directory named “dn” at the root (“/”) to store data blocks on the DataNodes.

mkdir /dn        

2.2 Configure “hdfs-site.xml” for DataNode: Update the Hadoop configuration to specify that the DataNode should store its data in the “/dn” directory.

echo "<configuration><property><name>dfs.datanode.data.dir</name><value>/dn</value></property></configuration>" > $HADOOP_HOME/etc/hadoop/hdfs-site.xml        

2.3 Configure “core-site.xml” for DataNode: Set the default file system to HDFS and assume the NameNode is running on localhost at port 9000.

echo "<configuration><property><name>fs.defaultFS</name><value>hdfs://localhost:9000</value></property></configuration>" > $HADOOP_HOME/etc/hadoop/core-site.xml        

2.4 Start DataNode: Launch the Hadoop Distributed File System, including the DataNode, using the “start-dfs.sh” script.

start-dfs.sh        

These steps ensure the proper configuration and initiation of DataNodes, crucial for distributed data storage.

Phase 3: Client Configuration

3.1 Configure “hdfs-site.xml” for Client: Update the client’s “hdfs-site.xml” to specify the default Hadoop file system and the address of the NameNode.

echo "<configuration><property><name>fs.defaultFS</name><value>hdfs://localhost:9000</value></property></configuration>" > $HADOOP_HOME/etc/hadoop/hdfs-site.xml        

This step ensures the client is properly configured to interact with the Hadoop cluster.

Phase 4: Checking Replication and Parallelism

4.1 Verify Connections on Ports: Check the connections on ports 9001 (NameNode) and 50010 (DataNode) on the NameNode to ensure proper communication.

sudo lsof -i :9001
sudo lsof -i :50010        

4.2 Upload File from Client Terminal: Demonstrate file upload from the client terminal to HDFS, showcasing the replication and parallelism capabilities.

hdfs dfs -copyFromLocal localfile /user/username/hdfspath        

4.3 Check Network Packets for Port 50010 at NameNode: Capture and analyze network packets on port 50010 at the NameNode using tcpdump.

sudo tcpdump -i any port 50010        

4.4 Check Network Packets at DataNode for Port 50010: Capture and analyze network packets on port 50010 at a DataNode using tcpdump.

sudo tcpdump -i any port 50010        

These steps provide insights into the connections, network packets, and parallelism during the file upload process in the Hadoop cluster.

By meticulously following these phases, you lay the foundation for a robust Hadoop cluster, configuring the NameNode, DataNode, and client while validating replication and parallelism in data storage and retrieval.

Thank You