User credentials on a master-job node setup

For configurations to be pushed from the master node to job nodes, you must be logged in as a CLC Server administrative user common to the master node and the job nodes. The user logged into the master, when node addition and configuration changes are performed, is the same user that logs in to the job nodes to perform changes.

When initially installed, all instances of the CLC Server have the same credentials for the default admin user, root (see Logging into the administrative interface). Logging in as the built-in root user using the default credentials is convenient when configuring a new setup. I.e. On a new setup, attach the job nodes before changing the root user's password and before changing the authentication mechanism.

Once the CLC Server software on all machines is up and running and the job nodes have been attached to the master, new users can be added, and passwords set, using the built-in authentications system, or a different authentication mechanism can be specified. The root user's password should be changed before the system is made available to users (details provided below).

To add a job node later, the administrative user you are logged in with must already be available, with the same credentials, on the job node to be attached. In many cases, the simplest route will be to log in as the CLC Server root user on the job node, which initially involves using the default password, and then change the root user's password to match that on the master node. The job node could now be attached when you are logged in as the root user on the master node.

Changing admin user passwords

Password changes must be done by a user with administrative privileges, and should generally be done on behalf of a different user, i.e. not by the same user that will be affected by the change being made.

For example, when changing the root user's password, log in as an administrative user other than root. This implies that before changing the root password, at least one user with administrative rights on the CLC Server should be available. Giving users administration rights is described in Giving users administration rights.

While not recommended, if you do not wish to have any administrative user for the CLC Server other than the root user, then changing the root user's credentials involves detaching the job nodes, and then manually updating the the root password on each job node as well as the master node. Then log out of the master node, log back in using the new root password, and re-attach the job nodes. The master and job nodes should now all have the same password for the root user.

Background information: When you are logged in as the root user and then change the root user's password, the login session becomes invalid. On a single server, you can just log out and log in again using the new password. However, on a master node with job nodes attached, communication issues between the master and job nodes arise as the login session on the master node becomes invalid, and the job nodes and the master will no longer have the same root password information.