Members of the W3C Service Modeling Language Working Group have
published Last Call Working Drafts for "Service Modeling Language,
Version 1.1" and "Service Modeling Language Interchange Format, Version
1.1." SML defines extensions to the W3C XML Schema language by adding
support for inter-document references and user-defined constraints.
This combination of features is very useful in building complex
multi-document models that capture structure, constraints, and
relationships. In the management domain, these models are typically
used to automate configuration, deployment, monitoring, capacity planning,
change verification, desired configuration management, root-cause
analysis for faults, etc. A "model" in SML is realized as a set of
interrelated XML documents. The XML documents contain information about
the parts of a service, as well as the constraints that each part must
satisfy for the service to function properly. Constraints are captured
in two ways: (1) Schemas: defining constraints on the structure and
content of the documents in a model. SML uses XML Schema (XML Schema
Structures, XML Schema Datatypes) as the schema language. In addition
SML defines a set of extensions to XML Schema to support references that
may cross document boundaries. (2) Rules: Boolean expressions that
constrain the structure and content of documents in a model. SML uses
Schematron (ISO/IEC 19757-3, Introduction to Schematron, Improving
Validation with Schematron) and W3C XPath for rules. One of the important
operations on the model is to establish its validity. This involves
checking whether all data in a model satisfies the schemas and rules
declared. This specification focuses primarily on defining the
extensions to XML Schema for references that cross document boundaries,
Schematron usage in SML, as well as the process of model validation.
The Last Call review period extends until 26-March-2008.
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