InformationWeek

ntegration servers are the latest approach to simplifying the complex task of integrating disparate enterprise applications, databases, and transaction systems. Integration servers play a key role in the development of distributed systems that span the Web, company networks, and partner systems. They help companies integrate packaged applications, custom software, and legacy systems.

These servers support one of two basic architectural models: the hub-and-spoke or the message-bus model (see "Integration Powered By E-Business," May 28). In the former, all applications connect to a central server, which performs message brokering to control communication, data translation, and process interactions between linked apps. The latter model connects disparate applications to a common backbone, which offers greater scalability and performance than the message hub. This approach requires that application adapters be installed on all integrated apps.

For this article, we looked at integration servers from CrossWorlds Software, SeeBeyond Technologies, Tibco Software, Vitria Technology, webMethods, and WRQ. Here's what we found:

CrossWorlds
CrossWorlds' design is a distributed hub-and-spoke architecture with the engine running on top of a Java Virtual Machine. For reliability, CrossWorlds has a built-in asynchronous transaction coordination engine, adapter-level fault tolerance, and support for clustering at the hardware level. Adapter uptime and downtime are reported in real time via the system manager, a proprietary management console included in the server.

CrossWorlds is also compliant with the Simple Network Management Protocol, which lets it integrate with third-party enterprise-management consoles. It has rudimentary security features that grant access to resources, such as adapters, business process models, and the development environment, on an individual user basis. For hierarchical security structures, integration with a Lightweight Directory Access Protocol server is required, for which CrossWorlds includes a packaged adapter.

A major differentiator for CrossWorlds is its dynamic configuration capability through its metadata repository. Once changes are made to the centralized metadata repository, they are automatically propagated to the respective adapters or components.

SeeBeyond Technologies
E-Business Integration Suite's architectural design is a component-based network-centric bus. For reliability, it has adapter-and queue-level fault tolerance and a built-in proprietary asynchronous transaction coordination engine. The ability to automatically restart adapters on failure is a key feature, but customization is needed to automatically shut down adapters. System notifications can be sent via E-mail, page, and wireless links.

SeeBeyond's process manager has powerful capabilities to define, control, and view compensating transactions. Nested processes are supported with drill-down views. In addition, the integration suite offers basic native report-generation capabilities, and it integrates with third-party products.

SeeBeyond offers tight integration with IBM's MQSeries middleware, which can be used in place of its proprietary messaging engine. The integration suite uses Secure Sockets Layer for data-stream encryption and bundles RSA Security Inc.'s public key libraries.

Although no packaged adapters are available for online transactional processing products such as BEA Systems' Tuxedo, SeeBeyond has customized integrations being used in the field. In addition, an adapter is available for integrating with IBM's CICS host environment.

Two things that set SeeBeyond's product apart are the Index Global Identifier and its registry. The Index Global Identifier is a cross-referencing engine that identifies users across all interconnected systems. The registry is its central repository for all adapter code, which also controls dynamic configurations of adapters. This lets companies centrally configure adapters and deploy them locally or to remote sites.

Tibco Software
ActiveEnterprise's architecture can support both a network-centric bus, and hub and spoke configuration, with TIB/Rendezvous as the backbone. A key differentiator is how interconnected applications communicate. Universal datagram protocol packets are serialized to ensure reliability and guaranteed receipt of all information. If packets don't get through, the software sends notifications.

Tibco's security offering bundles RSA's libraries for data encryption, and SSL is used for data-stream encryption. Tibco's integration suite also has certified integration capabilities with Netegrity SiteMinder, a third-party authorization engine. This is ideal for companies that use centralized security models.

Transaction coordination is built into ActiveEnterprise but can be supplemented by a third-party OLTP product, such as IBM's CICS and TX Series transaction monitor, for which Tibco has packaged adapters. Tibco also has an adapter for the Tuxedo transaction monitor, but it requires customization.

ActiveEnterprise is an intuitive tool for business users to model process flows. With the acquisition and tight integration of InConcert's software, Tibco is one of the few enterprise application integration vendors to offer both process automation and manual workflow capabilities, cohesively tied together.

Given ActiveEnterprise's capabilities and ease of use, it's well suited for a wide range of companies that face complex integration and process-modeling issues.