Joomla Multi Sites allows multiple domain names or sites to have their own joomla configuration file using the same joomla 1.5.x installation.

With this new feature you can share the same joomla installation directory and create different web sites.
As each site has its own joomla configuration, you can easily decide to share the same database and use a special database prefix (other than "jos_").
The setup of each configuration site consists in using the standard joomla installation mechanism.
In the administration of a 'Slave' site, you can re-install/uninstall extension previously installed on the 'Master' site.
The 'Master' site is the one where you have installed the Joomla MultiSites component and where you manage the 'Slave' sites.
Additional control are performed during the installation/uninstallation of an extension in a 'slave' site.
Before executing the standard joomla installation, it is verified that the extension you request to install has exactly the same name and same version number to avoid inconsistency between all sites.
This additional control is performed to ensure that you will overwrite the current installation with identical files that you originaly installed.
On 'slave' site, the uninstall of an extension consists in a joomla standard cleanup of the database. The files present on disk for this extension are not deleted to avoid disturb the other sites.

Templates and Languages are automatically shared between all sites.
Each website can select its own default template and languages.
The re-installation of thoses extension is therefore disabled from the 'Slave' sites.

As each slave sites use different table prefix, when the authentication is Joomla, this mean that each sites has its own user login. The users are not shared.
For external authentication like LDAP, by the definition of external system the users are shared between all websites.

Joomla Multi Site is a Joomla native 1.5 component.

Maintenance Advantage

Robustness

To increase the robustness of this Joomla Multi Sites extension, the number of core file to patch has been reduced as much as possible.Only 5 core joomla files require to be patched.
In each file, the patches consists in modifying 2 lines and adding 1 line.
The patches are not deployed at the installion of the component.
To avoid loosing any files, a backup is performed during the installation of the component. This allow restoring files if you decide to uninstall the component.
When you decide to install the patches, the sub-menu "check patches" give you a supervision of the files that need to be patched in aim to let slave sites wroking properly.

The Joomla Multi Sites is delivered with a copy of the standard Joomla installation directory to ease the deployment of this component.
It is also delivered with a backup of the original joomla files in case where you have deleted the backup realized at the installation of joomla multisites compoent.

Possible architecture

Single database

Joomla Multi Sites can use a single database for all the websites. In this case, the separation of the data of each websites is guarantee with different database table prefix.
The "jos_" table prefix can not be used in this scenario.
This kind of architecture can be used when you start a fresh installation and when you are limited in the number of database you can create.

Two databases (1 master and 1 slave)

When using two databases, the master database can use the "jos_" table prefix.
The second database is used to store the slave sites. The "jos_" table prefix is forbidden in the slave database.
This kind of architecture is adviced when you are limited in the number of database and when you want install Joomla Multi Sites in an existing website (master site).

As many databases than there are websites

This architecture is the most flexible architecture and corresponds to the default Joomla Installation procedure.
The "jos_" table prefix is allowed for each website.

Summary

The choice of the architecture depend on:

• The maximum number of database that your provider authorise;
• The disk quota (disk space) used by the databases
• the need to use "jos_" as tabel prefix.
  The "jos_" table prefix can only be used when there is only a single website stored in the database.
  As soon there are multiple websites stored in the same database, the "jos_" table prefix is forbidden.

Compatibility

JMS were oriiginally been developed under Joomla 1.5.2 and used intenally.
The first public distribution started with Joomla 1.5.3 and now upgraded with Joomla 1.5.8.
JMS works perfectly with all Joomla 1.5.x due to the limited patches required.

Several external components were tested with Joomla Multi Sites.
Following components works perfectly without any patches:

• DOCMAN 1.4.0rc3
• FAQ for Joomla (see www.faq2win.com)
• EventList 1.0 Beta
• Phoca Gallery 2.0.0

Reported as working without patches by our customers

• Joomla flash uploader
• MorfeoShow

Other extension may have problems when they contain their own Installation system. This is the case for example of XMAP and Community Builder that have an extension installer or a Plugin Installer.
We deliver Joomla Multi Sites with patches for:

• VirtueMart 1.0.15 & 1.1.x to accept multiple SECUREURL depending on the domain name;
• XMAP 1.1 to accept extension re-installation from a Slave site;
• Community Builder 1.1 Stable, CB 1.2 RC2 and RC3 to accept Plugin re-installation from a Slave site.

Don't hesitate to contact us if you have any doubt about a specific component.

Documentation and Demo

In the users manual, you have a description of each functionalities.
The two major functionalities are:

• Check, Install and Uninstall the patches for the core joomla and possible extensions
• Manage the slave website to define the relation between the domain name and a directory where will be stored the specific configuration file.

A document "demo installation" is also available to guide the new users in the different steps of the installation of Joomla Multi Sites. It also highlight some points that must be respected to guarantee that each website is independant.

Visit also our FAQ where we you will find the answer to some frequently asked questions.