The original Call for Participation for this
TC may be found at http://lists.oasis-open.org/archives/tc-announce/200505/msg00004.html.
[draft
rev 1 -- changes in red bold]
The charter for this TC is as follows.
Name and abbreviation
OASIS Web Services Reliable Exchange
Technical Committee (WS-RX)
Purpose
The purpose of the OASIS Web Services
Reliable Exchange (WS-RX) Technical Committee (TC) is to define a
protocol for reliable message exchanges between two Web services,
through continued development of the Web Services Reliable Messaging
specification [1] submitted to the TC as referenced in this charter and
to define a mechanism by which Web services express support for
reliable messaging as well as other related useful parameters. This
mechanism will be based upon the Web Services Reliable Messaging Policy
Assertion ("WS-RM Policy") specification [2] submitted to the TC.
Scope
The TC will accept as input the February
2005 Version 1.0 of the WS-ReliableMessaging [1] and WS-RM Policy [2]
specifications (the Input Documents) from BEA Systems, IBM, Microsoft,
and TIBCO Software. Other contributions and changes to the input
documents will be accepted for consideration without any prejudice or
restrictions and evaluated based on technical merit in so far as they
conform to this charter. OASIS members with extensive experience and
knowledge in these areas are particularly invited to participate.
The scope of the TC's work is to continue
development and refinement of the input documents to produce as output
modular specifications that standardize the concepts, WSDL documents
and XML schema renderings required to provide reliability assurances to
message exchanges between two parties that conform to the
specifications.
Reliable messaging systems can generally be
described using a four agent model. In this model there is an
Application Source, a Reliable Messaging Source that acts on behalf of
the Application Source, an Application Destination and a Reliable
Messaging Destination that acts on behalf of the Application
Destination. Message Transfer is the function of moving messages from a
Reliable Message Source to a Reliable Messaging Destination. This TC
will provide protocols for the reliable message transfers that occur
between Reliable Messaging Sources and Reliable Messaging Destinations.
The TC will not develop additional mechanisms by which a Reliable
Messaging Source captures messages from an Application Source or
mechanisms by which a Reliable Messaging Destination delivers messages
to an Application Destination.
A reliable message transfer is one in which
certain reliability assurances exist between two parties even in the
presence of a variety of failures. There can be multiple, concurrent
and independent reliable exchanges between two parties. Reliability
assurances make statements about the type of reliability provided to a
message exchange.
The specifications will define a set of
basic concepts required for the correct functioning of message
exchanges with reliability assurances. The specifications will render
these concepts as a specific set of restrictions over SOAP messages
including XML schemas and WSDL documents.
The specific reliability assurances in the
scope of the TC are:
- At Least Once: Messages are transferred
at least one time or an error is raised on at least one of the
endpoints. It is possible that some messages are transferred more than
once.
- At Most Once: Messages are transferred at
most one time or an error is raised on at least one of the endpoints.
It is possible that some messages are not transferred.
- Exactly Once: Messages are transferred at
least one time and at most one time or an error is raised on at least
one of the endpoints.
- Ordered: Messages are transferred in the
order in which they are sent.
These reliability assurances can be combined
and certain combinations are of particular interest due to their
widespread application: Exactly Once and Ordered (also referred to as
Exactly Once Ordered).
The specifications developed by the WS-RX TC
will define mechanisms that support and allow the implementation and
expression of reliability assurances, at most once, at least once,
exactly once, ordered, and will not define mechanisms for applications
to manifest reliability assurances.
The specifications developed by the WS-RX TC
will define elements and relationships among elements that enable the
implementation of the following functions which support the reliability
assurances in the scope of the TC:
- Reliable establishment and teardown of
one or more independent shared contexts between two parties within
which reliability assurances apply to one-way or two-way messaging.
- A mechanism which two parties can use to
perform one-way or two-way reliable messaging within a reliable context.
- Ensures timely destination amnesia
detection. Destination amnesia is the condition resulting from
catastrophic failure in which a Destination loses the shared context
required by reliability assurances.
- At Most Once reliability assurances even
in the case of Destination amnesia.
- Efficient message retransmission and
acknowledgment.
- Duplicate message detection.
- Detection of out-of-order messages and
discovery of the correct order of messages.
- Unique identification of messages within
a reliable context
- Acknowledgement of all messages within a
reliable context
- RM protocol violation detection and the
raising and transmission of related fault information.
- Efficient preservation of the integrity
of reliable contexts by composition with WS-Security or other SOAP
security mechanisms.
- Expression of support for the
specifications using the WS-Policy Framework [9] and binding of that
policy to a WSDL port.
- A binding of the reliable messaging
protocol elements to SOAP 1.1 and SOAP 1.2.
The specifications will uphold the basic
principles of other Web services specifications of independence and
composition and must be composable with the other specifications in the
Web services architecture, such as WS-Security [3], WS-Trust [4],
WS-SecureConversation [5], WS-Addressing [6], SOAP 1.1 [7], SOAP 1.2
[8], bindings of SOAP 1.1/1.2 to HTTP, WS-Policy [9], WSDL 1.1 [10] and
WSDL 2.0 [11]. The TC will also take into consideration
applicable work, such as the WS-I Basic Profile [12], the IBM Basic B2B
Profile [16]
published in April 2005, WS-Context [16], and WS-Reliability 1.1, an
OASIS International Standard published in November, 2004 [17].
The "Secure, Reliable, Transacted Web Services: Architecture &
Composition" white paper [13] published in 2003 and
the Web Services
Architecture
published by the W3C as a Working Group Note [15] provides
information on the Web services
architecture.
If an above specification is outside of a
standardization process at the time this TC moves to ratify its
deliverables, or is not far enough along in the standardization
process, any normative references to it in the TC output will be
expressed in an abstract manner, and the incarnation will be left at
that time as an exercise in interoperability.
While composition with other specifications
is a goal of the TC, it is also a goal to leave the specifics of how
that composition is achieved outside the scope of the RM specifications.
Each of the protocol elements will use
implementation and language neutral XML formats defined in XML Schema
[14].
Out of Scope: The following is a
non-exhaustive list. It is provided only for the sake of clarity. If
some function, mechanism or feature is not mentioned here, and it is
not mentioned in the Scope of Work section either, then it will be
deemed to be out of scope.
The TC will not define a mapping of the
functions and elements described in the specifications to any
programming language, to any particular messaging middleware, nor to
specific network transports.
The elements and/or mechanisms the TC
defines must be independent of issues and considerations that do not
affect an interoperable reliable messaging protocol.
Specifically: the TC is not concerned with
binding the specifications to specific underlying transports.
The TC and the specifications that it
producesdo not address considerations, such as durability related to
Sources' and/or Destinations' ability to satisfy reliability assurances.
Except for the elements directly related to
the functions in the scope of the specifications, the TC will not
prescribe the format of messages that are transferred reliably
according to the specifications.
The TC will make no assumptions about the
location of Application Sources relative to RM Sources and Application
Destinations relative to RM Destinations.
The TC will not attempt to define concepts
or renderings for functions that are of wider applicability including
but not limited to:
- Security (Encryption, Integrity and
Authentication)
- Addressing
- Policy languages and frameworks
- Routing
- Transactions and Compensation
Where required these functions are achieved
by composition with other Web services specifications.
The TC will not attempt to define
functionality duplicating that of any normatively referenced
specification in the input WS-ReliableMessaging or WS-RM Policy
specifications. If the referenced specification is outside of a
standardization process at the time this TC moves to ratify its
deliverables, or is not far along enough in the standardization
process, any normative references to it in the TC output will be
expressed in an abstract manner, and the incarnation will be left at
that time as an exercise in interoperability.
Deliverables
The TC has the following set of deliverables.
- A revised Web Services Reliable Messaging
Protocol specification. Committee Specifications are scheduled
for completion within one year of the first TC meeting.
- A revised Web Services Reliable Messaging
Policy Assertion specification. Committee Specifications are
scheduled for completion within one year of the first TC meeting.
These specifications will reflect
refinements, corrections or material technological improvements with
respect to the input documents and in accordance with this charter.
Ratification of the above specifications as
OASIS Standards, including a brief period to address any errata, will
mark the end of the TC's lifecycle.
The TC may choose to vary the number of the
specification documents and their titles.
IPR Mode
This TC will operate under the "RF (Royalty
Free) on RAND Terms" IPR mode as defined in the OASIS Intellectual
Property Rights (IPR) Policy, effective 15 April 2005.
Audience
The anticipated audience for this work
includes:
- Vendors offering Web services products;
- Other specification authors that need
reliable message delivery for Web services
- Software architects and programmers, who
design, write or integrate applications for Web services
- End users implementing Web services-based
solutions that require an interoperable, composable reliable messaging
solution.
Language
TC business will be conducted in English.
References
[1] WS-ReliableMessaging
http://schemas.xmlsoap.org/ws/2005/02/rm
[2] WS-RM Policy
http://schemas.xmlsoap.org/ws/2005/02/rm/policy
[3] WS-Security
http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0.pdf
[4] WS-Trust
http://schemas.xmlsoap.org/ws/2005/02/trust
[5] WS-SecureConversation
http://schemas.xmlsoap.org.ws/2005/02/sc
[6] WS-Addressing
http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/
[7] SOAP 1.1
http://www.w3.org/TR/2000/NOTE-SOAP-20000508/
[8] SOAP 1.2
http://www.w3.org/TR/soap12-part1/
http://www.w3.org/TR/soap12-part2/
[9] WS-Policy
http://schemas.xmlsoap.org/ws/2004/09/policy
[10] WSDL 1.1
http://www.w3.org/TR/2001/NOTE-wsdl-20010315
[11] WSDL 2.0
http://www.w3.org/TR/wsdl20-extensions
http://www.w3.org/TR/2004/WD-wsdl20-bindings-20040803
[12] WS-I Basic Profile
http://www.ws-i.org/deliverables/workinggroup.aspx?wg=basicprofile
[13] Secure, Reliable, Transacted Web
Services: Architecture & Composition
http://msdn.microsoft.com/webservices/understanding/advancedwebservices/default.aspx?pull=/library/en-us/dnwebsrv/html/wsoverview.asp
http://www-128.ibm.com/developerworks/webservices/library/ws-securtrans/index.html
[14] XML Schema
http://www.w3.org/TR/xmlschema-1/
http://www.w3.org/TR/xmlschema-2/
[15]
Web Services Architecture
http://www.w3.org/TR/ws-arch/
[16]
IBM Basic B2B Profile
http://www-128.ibm.com/developerworks/webservices/library/specification/ws-b2b/
[17]
WS-Context
http://www.oasis-open.org/apps/group_public/download.php/12416/WS-Context.zip
[18]
WS-Reliability 1.1
http://docs.oasis-open.org/wsrm/ws-reliability/v1.1/wsrm-ws_reliability-1.1-spec-os.pdf
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