Hadoop Cluster Administration Course: Guide for Hadoop Admin

Download CentOS by navigating to the official download page, selecting the 64-bit dvd image, choosing a mirror and version, and starting the download.

Set up a virtual machine in VirtualBox by naming the instance, selecting Linux 32-bit or 64-bit, enabling virtualization in BIOS, and configuring RAM and a dynamically allocated virtual hard drive.

Configure a virtual machine by attaching a CentOS ISO: adjust storage, uncheck floppy, select a virtual CD image, load the ISO file, and set the network adapter.

Shows how to install Java on virtual machines, including logging in, navigating directories, and running sudo yum install java to install a custom JDK.

Generate ssh key pairs across machines to enable passwordless, secure remote access. Configure a common user, install OpenSSH, and manage private and public keys for trusted logins.

Set up the Java environment by confirming the Java version, exporting JAVA_HOME, updating bashrc, and sourcing it to apply changes, ensuring Java 1.6.0 is active.

Create the elementary directory, copy a local file into it, and verify via dfs commands that the directory and file exist in the file system.

Learn how to manage Hadoop daemons, start and stop the NameNode and DataNode, and format the NameNode to recover from an inconsistent storage directory, ensuring a clean cluster restart.

create a parent directory to permanently store data within the directory tree, configure its ownership and permissions, and navigate through the abc and ebc directories to verify structure.

Learn how to access and monitor a Hadoop cluster via the browser interface, create directories, copy data with HDFS commands, and view job tracker and task tracker details.

Learn how to commission and decommission nodes in a Hadoop cluster, manage daemons across master and slave machines, and start or stop daemons while tracking added or removed servers.

Explore how to dynamically write data with different replication factors in Hadoop by creating a directory, copying a file into the DFS, and setting its replication to one, then verifying.

Rack awareness distributes blocks across racks to boost availability and performance, guiding replicas to different racks so not all copies reside on one rack.

Explore how adding and deleting files in a Hadoop cluster updates the fsimage, affects metadata and size, and how to view these changes through the browser interface and commands.

Learn how to manually connect to the namenode by stopping the secondary namenode to release directory locks, perform updates, and verify changes before restarting the secondary namenode.

Learn how to commission and decommission Hadoop cluster nodes, maintain availability with a minimum two-machine setup, and handle recommissioning to recover from node failures.

The hdfs balancer analyzes block placement and moves blocks to balance disk usage across the cluster, using a default 10 percent threshold or a custom value.

Explore how to restore the data within a Hadoop cluster as part of the Hadoop cluster administration course, focusing on data recovery concepts.

Distcp, the distributed copy tool, expands a list of files and directories into map tasks and copies partitions across cluster nodes using MapReduce.

Explore practical data backup with distcp and cp, learning how to copy files within a cluster and across clusters for reliable Hadoop data protection.

Learn to use distcp across a Hadoop cluster to copy data between data nodes and back up files across clusters.

Learn to recover a crashed namenode by inspecting running processes, stopping secondary nodes, and restoring the fsimage from the secondary using copy operations and checkpoint data.

Install and configure the NFS server, create a shared directory, grant read and write access via exports with sync, and start the NFS service to enable shared storage.

Delete the namenode's primary path and restart the namenode, then resolve directory inconsistencies by removing the primary directory from all references and checking logs.

Learn how to recover metadata from a secondary location to the primary location by recreating directories, setting ownership, and importing checkpoints to restore the primary metadata.