How to Uninstall Hadoop on Ubuntu

Hadoop is a popular open-source framework that allows for the distributed processing of large data sets across clusters of computers. While it’s a powerful tool for big data analytics, there might be instances where you need to uninstall it from your Ubuntu system, perhaps to free up space, resolve conflicts, or install a different version.

In this guide, we’ll walk you through the step-by-step process of uninstalling Hadoop on Ubuntu.

Step 1: Backup Your Data

Before making any changes to your system, it’s always a good idea to backup any important data. This ensures that you can restore your system to its previous state in case anything goes wrong.

Step 2: Stop All Hadoop Services

Before uninstalling, ensure that all Hadoop services are stopped.

sudo stop hadoop-hdfs-namenode
sudo stop hadoop-hdfs-datanode
sudo stop hadoop-yarn-resourcemanager
sudo stop hadoop-yarn-nodemanager

Step 3: Remove Hadoop Packages

Now, you can proceed to remove the Hadoop packages.

sudo apt-get purge -y hadoop\*

This command will remove all packages related to Hadoop.

Step 4: Delete Hadoop User and Group

If you created a specific user and group for Hadoop, you might want to remove them.

sudo deluser --remove-home hadoop-user
sudo delgroup hadoop-group

Step 5: Remove Configuration and Data Directories

Delete the directories where Hadoop configurations and data were stored.

sudo rm -r /usr/local/hadoop
sudo rm -r /app/hadoop/tmp

Step 6: Update System Repositories

After uninstalling, it’s a good practice to update the system repositories.

sudo apt-get update

Commands Mentioned

• sudo stop hadoop-hdfs-namenode – Stops the Hadoop HDFS NameNode service
• sudo apt-get purge -y hadoop\* – Removes all Hadoop related packages
• sudo deluser –remove-home hadoop-user – Deletes the Hadoop user and its home directory
• sudo rm -r /usr/local/hadoop – Removes the Hadoop installation directory

FAQ

1. Why might someone need to uninstall Hadoop?

   There are several reasons, including freeing up space, resolving software conflicts, or preparing to install a different version of Hadoop.

2. Is it necessary to stop all Hadoop services before uninstalling?

   Yes, it’s crucial to ensure that all Hadoop services are stopped to prevent data loss or corruption during the uninstallation process.

3. What happens if I don’t backup my data before uninstalling?

   If you don’t backup your data, you risk losing any important information stored within Hadoop, and it might be irretrievable after uninstallation.

4. Can I reinstall Hadoop after uninstalling it?

   Yes, you can reinstall Hadoop after uninstalling it. Ensure you follow proper installation guidelines when doing so.

5. Is it necessary to remove the Hadoop user and group?

   While it’s not mandatory, removing the Hadoop user and group ensures that all remnants of the software are removed, especially if you don’t plan to reinstall Hadoop.

Conclusion

Uninstalling Hadoop from Ubuntu is a straightforward process if you follow the steps outlined above. Always remember to backup your data before making any significant changes to your system.