SOA - Only XML ?

XML Services: A Brief Synopsis

•XML documents: Rendering a request or response as an XML document tends to be both CPU and memory intensive
•Networking: Passing textually-encoded XML documents is a poor use of bandwidth
•Connection Management: Connectionless HTTP is far more expensive than a socket
•Parsing: Validation and parsing of XML documents is extremely CPU intensive
•Summary: Big money, high latency


Appropriate Uses

•Exposing Platform-Independent Services
–XML-based services are the one thing that Java and Microsoft .NET can agree on
•Loose Coupling
–The service provider and the service consumer can be completely unknown to each other
•Public Network Capable
–Securable at the low level (e.g. HTTPS) and the high level (document signing, encryption, etc.)
•Defensible Uses
–Among separate applications
–Among different organizations

Other Options

XML-based SOA has appropriate uses
•SOA and its underlying principles do not require SOAP, XML, HTTP, etc.
•Java has a rich set of built-in capabilities for supporting SOA withinan application, such as:
–JMS –Message bus-based SOA
–RMI –Synchronous Java-centric remote invocation
•When the internal (Java) and external (XML) service interfaces are identical, then layer the XML-based interfaces on top ofthe higher-performing and more efficient Java API, and use the Java API within the app