| The WAS is IBM's core product for J2EE application support. IBM has differentiated WAS from other J2EE application servers in its scalability. From its inception, WAS was geared toward large-scale J2EE applications. It provides features supporting highly distributed applications and their management and support for the latest J2EE and Web services standards. It also addresses scalability and performance with support for deployment across multiple servers, load-balancing services, and automated performance tuning. Today, WAS is available in several configurations across a wide range of platforms, allowing any size of J2EE application to be deployed in the most cost-effective way possible. In contrast to Domino, WAS does not contain its own data manager. Instead, it relies on a relational database being available in the environment for application data storage or for J2EE components themselves , such as entity EJBs. One way that WAS provides access to those data sources is by leveraging the J2EE Connector Architecture (JCA). JCA defines a set of service contracts that a connector developer can expect will be available to the adapter at application runtime. The three basic services defined in JCA V1.0 include connection management, transaction management, and security management. Also unlike Domino is the fact that WAS relies on external sources for user directory (or what it terms "user registry") functions. For WAS (and J2EE), the user registry is required for user authentication relative to providing secure access to application components. WAS can be configured to use two categories of user registries ”local; for example, the Windows Active Directory or Unix user account file (/etc/passwd), or LDAP; that is, directories supporting the Lightweight Directory Access Protocol. The fact that Domino can provide LDAP access to its directory enables it to be considered for the WAS user registry. For single sign-on (SSO) support between Domino and WAS, and LDAP user registry must be used. We discuss the options for directory configuration in detail in Chapter 12, "Security and Single Sign-On." |
