Operating System Prerequisites

The operating system prerequisites include general Linux prerequisites and the user and users group needed to properly install and manage TimesTen Scaletout.

General Linux Prerequisites

On some Oracle Linux 8.x and RedHat 8.x systems, you must install the ncurses-compat-libs package (sudo yum install ncurses-compat-libs). Otherwise, cursor-based command recall and editing does not work in ttIsql.

On SUSE Linux Enterprise Server, you need to install libncurses5. To do this, run:

% zypper -n install libncurses

It is recommended that you enable stack traces for TimesTen. On Linux systems, use pstack or gdb to get a stack trace.

Understanding TimesTen Users Group and Operating System User

These topics describe and show how to create both the TimesTen users group and the operating system user (which will serve as the instance administrator):

TimesTen Users Group

TimesTen restricts access to the installation and the instances created from that installation to members of a single operating system group. This group, called the TimesTen users group, owns the installation and the instances created from the installation. Create this group (for example, timesten) and add the desired operating system users prior to installation. Once you create the TimesTen users group, you cannot change the name of the group or the group ID. See Create the TimesTen Users Group and the Operating System User.

Note:

The instance administrator's primary group must be the TimesTen users group.
Users who wish to access databases through TimesTen utilities or direct mode applications must be members of the TimesTen users group. This group can be the user's primary or secondary group.
Users connecting to a database through a client connection do not have to be members of the TimesTen users group.

Operating System User

The instance administrator for all instances in your grid is the operating system user who creates the active management instance. This user then becomes the instance administrator of all other instances in TimesTen Scaleout, including the second management instance and all data instances.

Note:

The instance administrator cannot be the root user.
The instance administrator configures the grid, creates and manages the databases in the grid, starts and stops the databases in the grid, performs all management activities, and performs backup and restore operations.
You cannot change the instance administrator after that administrator creates the active management instance.
The instance administrator is a member of the TimesTen users group. See TimesTen Users Group.
The instance administrator's user name and UID, and the group name and the group id (GID) of the TimesTen users group must be the same on all hosts in the grid, including the hosts on which the management and data instances exist, as well as any of the SCP repository hosts.
The installation and the instances must have the same owner (the instance administrator).

Create the TimesTen Users Group and the Operating System User

In this example, instanceadmin is the name of the operating system user and timesten is the name of the TimesTen users group.

Create the TimesTen users group. Name the group timesten with group ID 10000.
```
% sudo groupadd -g 10000 timesten
```
Create the instanceadmin user with UID 55000 and assign this user to the timesten primary group. Then, create a password for the instanceadmin user.
```
% sudo useradd -u 55000 -g timesten instanceadmin
% sudo passwd instanceadmin
```