ALL ABOUT CONFIGURATION SOA is all about leveraging existing IT assets, which is where integration comes in. Triaging legacy applications and exposing their discrete functionality as Web services via proprietary adapters enables existing IT assets to be loosely coupled. It allows integration to be about configuration, rather than undertaking a custom development effort. Call it composition over construction.

Appliances fit nicely into the SOA space because, by definition, they're configurable. They're not something you'll be developing code for. To the SOA architect, a SOA appliance can be thought of as a tangible service. It's a network component that offers discrete functionality to the SOA, and just like any other component in your SOA, it can be independently scaled up or out depending on the needs of the architecture.

The nature of a SOA gives organizations operational control over their architectures, which in turn lowers TCO. Appliances take this a step further, improving service levels in terms of performance and scalability for pieces of software that can't provide adequate levels of service themselves. To help you select the best SOA appliance for your needs, we'll be thinking inside the box and comparing SOA appliance offerings with security, acceleration, transformation, and parsing functionality in mind; see the Rolling Review box (below) for testing specifics.

SOA Appliances Rolling Review

The Invitation

This Rolling Review focuses on SOA appliances. To qualify, products must provide XML security, acceleration, transformation, and parsing functionality. We're evaluating based on ease of installation and configuration, breadth of functionality, management capabilities, features, and price. Each vendor must provide pricing for a product configuration capable of acting as an XML security gateway, in connection with XML acceleration requirements.

The Vendors

We've asked six vendors to send us their SOA appliances: Cast Iron, Cisco Systems, IBM, Layer7, Software AG, and Vordel.

The Test Bed

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We'll test SOA XML hardware appliances at our Real-World Labs at Synegen. Our Synegen lab houses application servers hosting several apps processing very large XML messages. Sample apps are J2EE-based, running on Apache Geronimo 1.1.1. Application servers are installed on Red Hat Enterprise Linux 4 running on Advanced Micro Devices processors with 2 Gbytes of RAM and 80 Gbytes of hard drive space.

Our application servers are sized to experience a high level of CPU utilization on the application server during XML processing. The application servers host fictitious applications, including e-commerce apps for a brick-and-mortar company with legacy apps downstream.

On the client side, we'll use Parasoft SOAtest 5.5 to perform scalability, functional, and performance testing. See the usage diagram (at right) for our test setup.

As seen in the diagram, SOA appliances enjoy a variety of deployment methods. For testing, our Linksys SRW2024P managed Gigabit Ethernet switch interconnecting the test client and application servers is configured with a SPAN port and two virtual LANs. The SPAN port allows us to simulate out-of-network testing. We'll evaluate application functionality by placing the SOA appliance directly between the application server and the switch port. After installation and configuration, we'll use the test client to invoke Web services that are beyond our privileges and attempt to send a large amount of data through a Web service call over HTTPS.

THE PREMISE

Rolling Reviews present a comprehensive look at a hot technology category, beginning with market analysis and wrapping up with a synopsis of our findings. Our extended testing span lets us accommodate today's accelerated revision cycles and focus our attention on individual products, while maintaining a consistent test bed.

GET CAUGHT UP
Find more Rolling Reviews, past and present: networkcomputing.com/rollingreviews/

Erik Pieczkowski is an enterprise architect with Synegen. His experience ranges from the design and development of high-performing, message-driven systems to building and deploying scalable SOAs.