1.2 ClearCase Hosts

ClearCase LT is a distributed application with a client/server architecture. Any development task (for example, execution of a single ClearCase command) may involve programs and data on both the ClearCase LT client and the server.

• Client host. Each ClearCase LT user works at a ClearCase LT client host, running programs such as cleartool, clearmake, and various ClearCase LT graphical user interfaces (GUIs), as well as other software (for example, development tools, a Rational Suite, and operating system utilities). ClearCase LT must be installed on each client host.

• ClearCase LT server. Every ClearCase LT client requires the services of a ClearCase LT server host to manage all of the client's access to VOB and view data. The ClearCase LT server runs server processes and supplies storage areas for VOB and view storage. A ClearCase LT client host can access only one ClearCase LT server. A ClearCase LT server host can support multiple VOBs and views, and can service the needs of many ClearCase LT clients.

• Rational license server host. One or more hosts in the network must be configured as license server hosts. ClearCase LT client hosts require a license to access data on the ClearCase LT server, and to perform most operations. The license server host may also be the license server for other Rational products. Because all Rational products use the same licensing mechanism, we recommend that you simplify license administration by using a single host to serve licenses for all Rational products in use at your site. See Chapter 5, Administering Licenses, for more information on this topic.

• Networkwide release host. One host in the network acts as the networkwide release host. A directory on this host stores an entire ClearCase LT release that has been extracted from the distribution CD. When necessary, ClearCase patches can be applied to a release area to update the entire release with the latest enhancements and defect fixes. Certain installation options allow ClearCase hosts running UNIX to access ClearCase programs and data through symbolic links to the release area instead of having the programs and data installed on local storage. ClearCase hosts running Windows do not access the networkwide release host after installation is complete. The networkwide release host does not need to run ClearCase.

NOTE: On Windows computers, ClearCase LT does not use a networkwide release host.

• ClearCase Web server host. If you want to use the ClearCase Web interface, you'll need at least one ClearCase Web server host. See Chapter 17, Configuring a Web Server for the ClearCase Web Interface, for more detail.