Presentation to the OMG's MARS Task Force in June, 2010 on the proposed specification "Web-Enabled DDS."

1. Web-Enabled DDS:
Revised Submission
MARS – Minneapolis, MN – June 2010
Presenter: Rick Warren, RTI
Submitting POCs:
 Angelo Corsaro, PrismTech:
angelo.corsaro@prismtech.com
 Hugues Vincent, Thales:
hugues.vincent@thalesgroup.com
 Rick Warren, RTI:
rick.warren@rti.com
document number: mars/10-06-02

2. Specification Process
RFP issued: September 2009 (San Antonio)
Initial submissions: March 2010 (Jacksonville)
 PrismTech
 RTI and eProsima, joint
 Thales
Revised submission: June 2010 (Minneapolis)
 All submitters, joint
 mars/10-05-03
Copyright © 2010 RTI - All rights Reserved 2

3. Progress Since Initial Submissions
Proposals consolidated into single document
 Alternatives appear side by side
 No attempt at reconciliation yet
Submitters’ meeting scheduled this week
Copyright © 2010 RTI - All rights Reserved 3

4. Differences Among Proposals: PIM
Object model proposed by RTI+eProsima
 Drastically simplified DDS model
 Procedural style
Object model proposed by Thales
 Somewhat simplified DDS model
 DDS LwCCM model
 OO/CRUD-oriented hybrid style
Access-control, session models
proposed by RTI+eProsima
Copyright © 2010 RTI - All rights Reserved 4

5. Differences Among Proposals: PSMs
SOAP PSM
 Proposed by
RTI+eProsima, Thales
REST PSM
 Proposed by all
submitters
Other PSMs (e.g.
RSS, Atom, XMPP)
 Nothing proposed yet
 Thales may provide
RSS and/or Atom
later
 Other contributions
welcome
Follow naturally
from PIMs
Copyright © 2010 RTI - All rights Reserved 5

6. TODO: Platform-Independent Model
Reconcile basic object model
 Q: How much of DDS should it expose?
 Tradeoff: Ease of use vs. expressiveness
 Q: Object-oriented vs. resource-oriented?
 Tradeoff: Ease of SOAP mapping vs. REST mapping
Layer DDS for LwCCM
 Q: To what extent is it alternative vs. supplemental?
 Q: What is relation to non-DDS LwCCM ports, connectors?
Integrate session management, access control
 Q: How to isolate users from one another?
 Prevent unauthorized access
 Prevent undesirable interference
 Q: How to integrate with existing standards/practices?
 e.g. WS-Security for SOAP, OpenID for REST
Copyright © 2010 RTI - All rights Reserved 6

7. TODO: Object Representation
XML Data Representation for samples
 Per DDS-XTypes
 Proposed by RTI+eProsima and Thales
JSON Data Representation for samples
 Proposed by all
 Valuable for JavaScript/AJAX apps
 Not yet formally defined
 Q: Should we keep it here, or move to DS-XTypes?
XML Entity Representation
 Not formally proposed yet, but maybe needed
 Q: When ‘PUT’ting new entity with REST, what is resource
representation?
 Just QoS (as proposed) insufficient: what about e.g. content
filters? Topic names?
 Q: REST-specific, or for SOAP too?
Copyright © 2010 RTI - All rights Reserved 7

8. TODO: Platform-Specific Mappings
General questions:
 Q: How much should PSMs resemble each other? PIM?
 Q: Must have equal expressiveness?
 e.g. Does same notification mechanism make sense for
SOAP vs. RSS?
 Q: Data representation orthogonal?
 e.g. JSON payload in SOAP message?
Copyright © 2010 RTI - All rights Reserved 8

9. TODO: Platform-Specific Mappings
SOAP
 It’s a jungle (of standards) out there.
 Q: SOAP version?
 1.2 is current standard; 1.1 much better supported
 Q: Relationship to current WS-* standards?
 e.g. WS-Eventing, WS-Notification
 e.g. WS-Security
REST
 Q: How resource-oriented vs. procedural?
 With right PIM, many controversies may be stylistic
Copyright © 2010 RTI - All rights Reserved 9

10. TODO: Compliance Points
Q: Which PSMs required?
Q: LwCCM required?
Q: Security required?
Copyright © 2010 RTI - All rights Reserved 10

11. Summary
Initial submissions contain strong ideas
 Focused on different aspects
…but still many holes to fill
Rick’s personal intuition:
 Synthesis won’t be copy-paste from one proposal
or another
 Will differ from all its 3 parents
 Get PIM right + get mapping style right =
PSMs will follow naturally
Copyright © 2010 RTI - All rights Reserved 11

12. Q & A
Copyright © 2010 RTI - All rights Reserved 12