Scope
One of the goals of SCA is to allow binding of SCA services and references to a variety of communication protocols and technologies in a declarative manner.
The primary focus of this TC will be to define bindings of SCA services and references to Web Service, Java Message Service (JMS) [8] and J2EE Connector Architecture (JCA) [9] technologies based on the following starting point contribution:
1. SCA Web Service Binding specification [1] 2. SCA JMS Binding specification[2] 3. SCA JCA Binding specification [3]
Other contributions may be made by TC Members on or after the first meeting of the TC. Such other contributions shall be considered by the TC Members on an equal basis to improve the original starting point contribution in a manner that is compliant with this charter.
For each SCA binding technology this TC will evolve the respective starting point contribution documents to produce one or more specification documents, XML Schema definition documents, possible WSDL documents, and possible language dependant artifacts as appropriate, from which compliant tools and runtimes for that SCA binding technology can be built.
The TC will not explore areas with general applicability and for which typically standards exist. The TC will make efforts to compose with existing standards providing such general functionality.
Following is a list of generic requirements for any binding specification.
For each binding specification, the TC shall identify the applicable subset and specify solutions accordingly.
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Specify whether the binding is applicable to both the Service and Reference elements
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Support for applying the binding to local and remotable interfaces
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Support for bi-directional and conversational interfaces (as defined in the SCA Assembly specification)
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Description of binding endpoint address formats, including how a URI scheme of a deployed binding can be determined
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Identify the intents that the binding type must provide or may provide
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Define how to share metadata across different binding instances
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Define how to correlate request/response messages
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Define how to configure request/response channels
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Define the mapping of SCA defined binding metadata to the relevant resource or service description standards
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Define the mechanism for selecting the operation targeted by a message, and binding the message data to the runtime representation (this functionality is commonly called as — operation selection/data binding)
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Define how to configure binding specific headers, user defined properties and interaction parameters
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Define how to support user authentication and security context propagation
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Ensure alignment with the generic binding architecture in the SCA Assembly Specification
In addition to the generic requirements above, each binding has specific requirements which are listed below. Note that the list of out-of-scope features and mechanisms is not exhaustive. In general, areas that are not explicitly listed as within the scope should be considered as out-of-scope.
SCA Web Service Binding
SCA Web Service Binding defines how a SCA service can be made available as a Web Service and how a SCA reference can invoke a Web Service.
The scope of the SCA Web Service Binding work, in addition to the generic list above, includes the following functions and mechanisms:
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Use existing WSDL 1.1 [4] and WSDL 2.0 [5] documents for the metadata required by SCA WS Binding, including any valid WSDL binding.
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Define SCA metadata to describe the Web Service binding of SCA services and references that use SOAP and are WS-I compliant
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Rules for generating WSDL 1.1 and WSDL 2.0 documents based on the SCA Web Service metadata
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Use of WS-Addressing [6] endpoint reference for describing the SCA Web Service binding
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Rules for determining the effective URI for the binding
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Mechanism for retrieving WSDL description for SCA services that are deployed using SCA Web Service binding
The following functions and mechanism are considered as out-of-scope for the SCA Web Service Binding work:
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Ensuring interoperability of SCA Web Service Bindings that utilize existing WSDL documents and those that include non standard WSDL extensions
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Defining SCA binding metadata for non-WS-I compliant Web services
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Defining SCA binding metadata for non-SOAP based Web services
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Mapping of the WSDL type system with other interface type systems such as Java interfaces
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Metadata specific to implementation of the services e.g. references to JAX-WS handlers to be invoked as part of dispatching a service request
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Support for SOAP intermediaries
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Defining new wire-level protocols for exchanging conversation identifiers and state. Conversation support may be addressed by reference to existing web service standards.
SCA JMS Binding
SCA JMS Binding defines JMS specific details to provide SCA service as a JMS resource or to consume a JMS resource as a SCA reference
The scope of the SCA JMS Binding work, in addition to the generic list above, includes the following functions and mechanisms:
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Binding of SCA services and references to existing or new JMS resources (destinations or connectionFactories)
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Binding of SCA services and references to existing or new activationSpecs for JCA 1.5 compliant JMS resource adapters
SCA JCA Binding
SCA JCA Binding defines JCA specific details for access and connectivity to EIS systems external to an SCA system. JCA Binding can be used for SCA services and references.
The scope of the SCA JCA Binding work, in addition to the generic list above, includes the following functions and mechanisms:
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Configuration of connection parameters for access to EIS via JCA
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Support for managed and unmanaged environments (as defined in the J2EE Connector Architecture specification [9])
The following is considered as out-of-scope for the SCA JCA Binding work:
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Specific support for any particular EIS system
Other Bindings
The TC MAY define other bindings explicitly listed below:
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HTTP
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REST
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SMTP
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FTP
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SIP
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SNMP
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JSON-RPC
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ATOM
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RSS
Upwards Compatibility
There are no formal requirements for upwards compatibility from the input documents to this TC. This is to ensure that the TC has maximum freedom of action in defining the OASIS standard. However it is recognized that there will be early implementations in the marketplace based upon these input documents and careful consideration must be applied to any change of feature/ function that would cause incompatibilities in the OASIS standard at:
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Source Code level
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Compiled Object Code
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XML data definitions
At minimum, known enhancements to the input documents that will cause compatibility issues with early implementations in the marketplace will be specified in a chapter in the specification offering migration guidance.
Conformance
In line with the OASIS TC process, the TC will produce normative conformance information describing the normative characteristics of the specifications and specific statements about what an implementation must do to conform to the specifications, what aspects are optional (if any).
Test Suite
The TC will produce a test suite for each binding which can be used to test conformance to the specifications which will include:
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Describe a series of valid and invalid test cases which cover as much as is practical of the conformance statements of the specifications produced by this TC, with a description of each of the artifacts involved, constraints on the environment, the test case characteristics and their expected behavior.
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The provided artifacts should be independent of implementation language. The artifacts may include SCA composites expressed in XML, WSDL interface files, and XSD files, sca-definition.xml files along with other similar files that express the required characteristics of the environment for each test.
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Example implementations and bindings may form part of the test suite, and are only provided as working samples which can be replaced by other specific implementations and bindings.
The test suites shall be packaged separately from the specifications produced by the TC and will contain a set of materials including but not limited to SCA composites and related SCA files, WSDL files, XSD files.
The TC shall develop the test suites in collaboration with other TCs within the Open-CSA Member Section.
The following material should be considered as best practice for the preparation of conformance and test suite materials:
Deliverables
The TC has the following set of deliverables:
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A revised SCA Web Services Binding specification inclusive of XML Schema and other ancillary documents.
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A revised SCA JMS Binding specification inclusive of XML Schema and other ancillary documents.
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A revised SCA JCA Binding specification inclusive of XML Schema and other ancillary documents.
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A complete Test Suite specification for each binding, including documents and the related materials described in the scope section.
All of the above deliverables are scheduled for completion within 12 months of the first TC meeting.
The TC may decide to modularize and produced more number of specification documents out of the starting point contribution or on the contrary the TC may decide to merge and produce less number of specification documents than the starting point contribution. Similarly, the TC may decide to change the names of the documents included in the starting point contribution.
Exit Criteria
The TC shall define concrete exit criteria that include at least two independent offerings that implement and are compliant with the all normative portions of specifications and demonstrate interoperability and portability as appropriate. Note that these are minimums and that the TC is free to set more stringent criteria.
Maintenance
Once the TC has completed work on a deliverable and it has become an OASIS standard, the TC will enter "maintenance mode" for the deliverable.
The purpose of maintenance mode is to provide minor revisions to previously adopted deliverables to clarify ambiguities, inconsistencies and obvious errors. Maintenance mode is not intended to enhance a deliverable or extend its functionality.
The TC will collect issues raised against the deliverables and periodically process those issues. Issues that request or require new or enhanced functionality shall be marked as enhancement requests and set aside. Issues that result in the clarification or correction of the deliverables shall be processed. The TC shall maintain a list of these adopted clarifications and shall periodically create a new minor revision of the deliverables including these updates. Periodically, but at least once a year, the TC shall produce and vote upon a new minor revision of the deliverables.
