Tool Mentor: Creating Multiple Sites Using Rational ClearCase
Purpose
This tool mentor describes the benefits of using the Rational ClearCase MultiSite product.
This section provides links to additional information related to this tool mentor.
What does ClearCase MultiSite do for your company?
The ClearCase MultiSite product is an add-on product to ClearCase used to distribute software development across different geographical locations. For example, if your company has developers in Boston, San Francisco, and Bangalore, you can give every developer local, real-time access to the source code repository (the versioned object base, or VOB). With MultiSite, each site has its own copy (replica) of the VOB and all developers can work in parallel on the source files without collisions.Conflicting changes at different sites are prevented by ClearCase MultiSite's mastership scheme. Most ClearCase objects can be mastered by only one replica, and only those developers who use that replica can modify the object. MultiSite has facilities you can use to share control of source code elements so multiple developers can work on the same source file in turn.
Instead of "throwing changes over the wall", you can use the synchronization tools supplied with ClearCase MultiSite to send changes among replicas as often as site connectivity allows. If you have IP connections, you can use MultiSite's shipping mechanism and configurable scripts to synchronize replicas frequently and automatically, giving developers at other sites access to the very latest changes made at your site. If you do not have IP connections, you can choose another synchronization method (for example, electronic mail, ftp, or magnetic tape) that's appropriate to your configuration.
Do you need ClearCase MultiSite?
You should consider using ClearCase and ClearCase MultiSite if you need to distribute development among several different locations and it's impractical for developers to remotely access VOBs. An additional benefit to using MultiSite is that you can use it as a backup mechanism by creating a replica in a different region at your site and synchronizing it frequently with the primary replica. By backing up the secondary replica instead of the primary replica, you can allow development to continue unhindered in the primary replica. Also, if the primary replica's host has a catastrophic disk crash, you can put the backup replica into use to avoid development downtime.
For more information
about this product, see the 
ClearCase
MultiSite information page on the Rational
Web site, contact your Rational sales representative, or see the ClearCase
MultiSite Administrator's Manual.