Disable SELinux, PackageKit, and check the umask Value

To disable SELinux, and PackageKit, and to check the umask value during the Ambari setup, perform the following steps:

1. For the Ambari setup to function, you must disable SELinux. On each host in your cluster, enter:

setenforce 0

2. On an installation host running RHEL with PackageKit installed, open /etc/ yum/pluginconf.d/refresh-packagekit.conf using a text editor. Make the following change: enabled=0

3. UMASK, a short name for "User Mask" or "User file creation MASK, determines the default permissions that are assigned when a new file or folder is created on a Linux system. Typically, many Linux distributions set the default umask value to 022. This means that when a new file or folder is created, it is given read (4), write (2), and execute (1) permissions for the owner (user), and read and execute permissions for the group and others, results in permissions of 755.

If the umask is set to 027, it grants read, write, and execute permissions of 7 for the owner and read and execute permissions of 5 for the group, while others have no permissions.

Ambari, ODP, and ODP support umask values of 022 (0022 is functionally equivalent), 027 (0027 is functionally equivalent). These values must be set on all hosts.

UMASK Examples:

• Setting the umask for your current login session:

umask 0022

• Checking your current umask:

umask

• Permanently changing the umask for all interactive users:

echo umask 0022 >> /etc/profile

Download and Set up Database Connectors

Ambari and components such as Hive, Ranger, and NiFi rely on an operational database. When installing, you can choose to use an existing database or let Ambari set up a new one. To ensure Ambari connects to your chosen database, you need to download the required database drivers and connectors from the database vendor prior to the installation. As part of your setup process, it is essential to configure these database connectors alongside your environment setup, as explained in the upcoming section, to streamline your installation or upgrade: Using an Existing Database or Installing a Default One.