Editing Cluster and its component Understanding (section)

=== ⁠1.9.1. Conga ===
'''Conga''' is an integrated set of software components that provides centralized configuration and management of Red Hat clusters and storage. '''Conga''' provides the following major features: 

* One Web interface for managing cluster and storage 
* Automated Deployment of Cluster Data and Supporting Packages 
* Easy Integration with Existing Clusters 
* No Need to Re-Authenticate 
* Integration of Cluster Status and Logs 
* Fine-Grained Control over User Permissions 

The primary components in '''Conga''' are '''luci''' and '''ricci''', which are separately installable. '''luci''' is a server that runs on one computer and communicates with multiple clusters and computers via '''ricci'''. '''ricci''' is an agent that runs on each computer (either a cluster member or a standalone computer) managed by '''Conga'''. 

'''luci''' is accessible through a Web browser and provides three major functions that are accessible through the following tabs: 

* '''homebase''' — Provides tools for adding and deleting computers, adding and deleting users, and configuring user privileges. Only a system administrator is allowed to access this tab. 
* '''cluster''' — Provides tools for creating and configuring clusters. Each instance of '''luci''' lists clusters that have been set up with that '''luci'''. A system administrator can administer all clusters listed on this tab. Other users can administer only clusters that the user has permission to manage (granted by an administrator). 
* '''storage''' — Provides tools for remote administration of storage. With the tools on this tab, you can manage storage on computers whether they belong to a cluster or not. 

To administer a cluster or storage, an administrator adds (or ''registers'') a cluster or a computer to a '''luci''' server. When a cluster or a computer is registered with '''luci''', the FQDN hostname or IP address of each computer is stored in a '''luci''' database. 

You can populate the database of one '''luci''' instance from another '''luci'''instance. That capability provides a means of replicating a '''luci''' server instance and provides an efficient upgrade and testing path. When you install an instance of '''luci''', its database is empty. However, you can import part or all of a '''luci''' database from an existing '''luci''' server when deploying a new '''luci''' server. 

Each '''luci''' instance has one user at initial installation — admin. Only the admin user may add systems to a '''luci''' server. Also, the admin user can create additional user accounts and determine which users are allowed to access clusters and computers registered in the '''luci''' database. It is possible to import users as a batch operation in a new '''luci''' server, just as it is possible to import clusters and computers. 

When a computer is added to a '''luci''' server to be administered, authentication is done once. No authentication is necessary from then on (unless the certificate used is revoked by a CA). After that, you can remotely configure and manage clusters and storage through the '''luci''' user interface. '''luci''' and '''ricci''' communicate with each other via XML. 

The following figures show sample displays of the three major '''luci''' tabs: '''homebase''', '''cluster''', and '''storage'''. 

For more information about '''Conga''', refer to ''Configuring and Managing a Red Hat Cluster'' and the online help available with the '''luci''' server. 

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[[Image:luci-homebase-tab.png]]

'''Figure&nbsp;1.21.&nbsp;luci homebase Tab'''

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[[Image:luci-cluster-tab.png]]

'''Figure&nbsp;1.22.&nbsp;luci cluster Tab'''

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[[Image:luci-storage-tab.png]]

'''Figure&nbsp;1.23.&nbsp;luci storage Tab'''