J2EE Architecture and security

CollabNet TeamForge is a J2EE application that employs three-tier architecture to provide a secure environment for mission-critical data.

In a multi-tier architecture, access to each tier is restricted to the tier above it, effectively securing the tiers behind the firewall. For example, while clients (users accessing the system through a web) access the web server, they neither have access to the application and backend servers nor are they aware of their existence.

Similarly, the web server itself does not have access to the backend servers (database, SCM, mail etc.)

Exceptions to this rule include:

• Direct client access provided to the SCM servers. SCM servers are accessed across the firewall typically through SSH protocol (for CVS), or HTTP or HTTPS (for Subversion). SCM server data is also accessible in a view only mode through the web interface.
• Clients must have access to the mail server for posting messages to mailing lists.
• Mail server must have access to deliver messages across the firewall.

Clients can also access the SOAP APIs through the web server. The web server in turn forwards SOAP requests to the application server for processing.